Corrie Mckeague and his mysterious disappearance

Corrie Mckeague was last seen in Bury St Edmunds at about 03:20 BST on 24 September

Seconds after this CCTV picture was taken, airman Corrie Mckeague turned to the right and disappeared into the shadows. Who is he and how did he vanish without trace?

Tucking into takeaway food on a mild autumn night, Mr Mckeague appeared to be in good spirits. He'd just played a game of paper, scissors, stone with a stranger.

It was 03:25 BST on Saturday, 24 September and he had been on a drunken night out with friends in the Suffolk town of Bury St Edmunds.

No-one has seen or heard from him since.

Who is Corrie Mckeague?

Mr Mckeague is from Dunfermline, Fife, but was posted to RAF Honington in Suffolk

Corrie Mckeague was born in Perth and brought up in Cupar, Fife, with his two brothers Darroch, 21, and Makeyan, 25.

Their parents separated when Mr Mckeague was nine and the boys moved 28 miles (45km) away to Dunfermline with their mother Nicola Urquhart.

At St Columba's High School in the town, Mr Mckeague had longed to become a Royal Marine but he initially went on to train to become a hairdresser at Adam Smith College in Kirkcaldy.

After realising hairdressing was not the career for him, he departed for Perth College University of the Highlands and Islands to become a fitness trainer.

Missing airman is a 'social hand grenade', says mum

It was then he decided to join the Royal Air Force and was posted to RAF Honington in October 2013.

He spent three months training before passing out - something his grandmother Mary Mckeague described as his family's "proudest day".

Mr Mckeague is a gunner in No 2 Sqn, RAF Regiment.

He is white, 5ft 10ins (1.78m) tall, of medium build, with short light brown hair.

His mother has described him as "gregarious", "funny" and someone who "loves to be the centre of attention".

"You don't forget Corrie if you meet him once," she said.

Mr Mckeague has a cross-breed puppy named Louell, which his family said he "loves to bits", and he had made plans to visit his grandparents at Halloween.

What do we know about the night he vanished?

Corrie Mckeague was last seen walking alone in Bury St Edmunds

Mr Mckeague had intended to head into Bury St Edmunds on 23 September with a group of friends from the air base, but due to a misunderstanding he had been left behind.

Instead, he drove himself into the town, about nine miles (15km) from the base.

He parked his BMW Z4 on Robert Boby Way just after 22:00 BST and spent an hour on the phone to his brother Darroch, making plans for the following weekend.

Mr Mckeague then went to join his friends.

The group went to the So Bar on Langton Place where they joined in a song with musician Nick Lowe.

The singer said Mr Mckeague was "quite a regular" in all of the bars.

Posters have been distributed far and wide in the search of Mr Mckeague

Mr Mckeague and friends then headed over to the Wetherspoon Corn Exchange pub at about 23:30 BST.

Megan Manning, who was there on the night, said: "He was coming up to loads of different tables, saying 'hello' to everyone. He was chatty; he was nice - a nice boy."

She said he was "memorable" because of the outfit he was wearing that night: a light-pink Ralph Lauren shirt, white jeans and a pair of Timberland suede boots.

Mr Mckeague and his friends left the Corn Exchange at about 00:30 BST and went to Flex nightclub on St Andrew's Street, just a minute's walk away.

Manager Ben Manning said he had asked Mr Mckeague if he was drunk, to which he said Mr Mckeague replied "yes", told him "I love you" and gave him a hug before "stumbling" inside.

Mr Mckeague visited So Bar and The Corn Exchange before going to Flex nightclub

Just after 01:00 BST, Mr Mckeague was escorted out of Flex by doorman Will Hook.

Mr Hook said the serviceman had "consumed enough alcohol" to draw attention to himself and "amicably" agreed to leave.

It was then that he became separated from his friends.

He bought burgers, a kebab and a bag of chips from his regular place, Pizza Mamma Mia, on St Andrew's Street North, where he seemed "happy" and played rock, paper, scissors with a stranger.

He could be seen eating his food as he passed a CCTV camera opposite The Grapes pub on the corner of Brentgovel Street and St Andrew's Street at about 01:20 BST.

He took a nap for about two hours in the doorway of electrical store Hughes on the corner of Brentgovel Street and St John's Street.

At 03:08 BST, Mr Mckeague forwarded a photo of a previous night out to a friend from his phone.

Mr Mckeague turned right into a loading bay area, known as the "Horseshoe", behind Greggs, at 03:25 BST.

The area is closed off by buildings and the rooftops have been searched and analysed by police.

It has been proven that an individual cannot leave the area on foot without being seen on CCTV, but Mr Mckeague was not caught on camera again.

What has happened since?

Mr Mckeague's father Martin and grandparents Mary and Oliver offered a five-figure reward

RAF Honington reported Mr Mckeague's disappearance to police on Monday, 26 September when he did not turn up to parade at 11:30 BST.

The base would ordinarily report a serviceman AWOL but Mrs Urquhart said he was treated as a missing person straight away.

She said this was partly because of heightened security after the attempted abduction of a serviceman close to RAF Marham in Norfolk in July, and also because Mr Mckeague's disappearance was "so out of character".

Police first informed the media of his disappearance on Tuesday, 27 September and released CCTV footage of him in Brentgovel Street the next day.

Here's what has happened since:

• 4 October: It is revealed that his mobile phone had been tracked moving 12 miles (19km) away to Barton Mills hours after he was last seen.

• 21 October: Further footage is released, showing his last confirmed sighting.

• 24 October: A driver reports seeing a man walking near the Hollow Road industrial estate on the day Mr Mckeague disappeared.

• 15 November: Part of the A14 near Bury St Edmunds is closed while police carry out a roadside search.

• 5 December: His grandparents Mary and Oliver Mckeague offer a "five-figure" reward for information leading to his discovery.

• 8 December: A crowdfunding campaign to hire a private investigator to search for Mr Mckeague raises £20,000 within two days and police release CCTV footage of 10 people they want to speak to.

• 7 December: Mr Mckeague's mother Mrs Urquhart offers a £50,000 reward, made possible by an anonymous local business couple.

• 9 December: Mrs Urquhart says she has "lost faith" in police over their search for her son.

• 16 December: Outgoing RAF Honington commander Gp Capt Mick Smeath speaks of Mr Mckeague's friends' hopes that he will be found.

• 17 December: A search organised by Mrs Urquhart takes place at an area of forest near RAF Honington.

• 20 December: Mr Mckeague's uncle Tony Wringe expresses anger over a seemingly bogus fundraising website set up in his nephew's name.

More than 6,000 hours have been spent searching for Mr Mckeague and thousands of frames of CCTV footage trawled through.

The Find Corrie Facebook page quickly gained more than 80,000 followers and there has been a huge campaign on Twitter to locate him.

What are the theories about what happened?

Mr Mckeague walked down Brentgovel Street

When Mr Mckeague was first reported missing, it was thought he may have attempted to walk back to RAF Honington.

One theory was that he was hit by a car and was dead in a ditch somewhere en route.

A stretch of the A14 between the Moreton Hall and Rougham junctions was closed off while police and Suffolk Lowland Search and Rescue carried out extensive searches.

British Transport Police has also helped Suffolk Police with searches along the railway line from Bury St Edmunds, and a section of the A1101 between the Fiveways roundabout at Barton Mills and Icklingham was closed while officers conducted further searches along it.

Searches have also been carried out along the A11.

Mrs Urquhart said a forest near RAF Honington could be "confidently crossed off" after volunteers searched the area

Another theory is that he was in one of the bins at the "Horseshoe" area, which was then taken to a landfill site.

Signals showed his Microsoft Lumia 435 mobile phone had moved to nearby Barton Mills, where there is a landfill site, and police searched a bin lorry after finding its route matched the movements of the device.

However, it was found that the weight of the bin lorry's load was 15kg (33lb) - too light to have contained Mr Mckeague.

As a result, the lorry was released and the landfill site was not searched.

The phone, however, has still not been found.

Could Corrie have been harmed by someone?

Nicola Urquhart said RAF Honington reported her son as missing rather than AWOL as "they knew something was wrong"

"Third party" involvement was quickly ruled out by police, but the idea has not been dismissed by Mr Mckeague's mother.

Mrs Urquhart said for her son to have vanished from the "Horseshoe" area, he must have been taken by someone else in a vehicle.

Suffolk Police has since said officers continued to consider "every possibility".

There has been some speculation of kidnap after the attempted abduction of an airman from RAF Marham in Norfolk in July, but this has not been substantiated by police.

Mr Mckeague's family have categorically said they do not believe he "went AWOL".

Although she has declined to elaborate further, Mrs Urquhart has been critical of the police investigation, saying police had "utterly destroyed" her confidence that they would find her son.

She organised her own search on 17 December.

The search goes on for Mr Mckeague

Suffolk Police has maintained officers are using an "inordinate" amount of resources and are exploring "every possibility".

The force said it was treating the case as a missing person investigation, not a murder investigation.

Nevertheless, police have said the level of resources deployed is similar to that of a murder investigation, with extensive searches by police dogs and forensic officers.

More than £26,000 has gone towards the investigation so far, according to figures from a Freedom of Information request.

Yet, three months on, Mr Mckeague's whereabouts are as big a mystery as the night he disappeared.