Murdered Sian O'Callaghan's boots and a shotgun found by police

Sian O'Callaghan was murdered by taxi driver Christopher Halliwell

Boots belonging to a woman who was murdered three years ago have been found, police say.

Sian O'Callaghan, from Swindon, was killed by taxi driver Christopher Halliwell, who had picked her up outside a nightclub.

The boots and a shotgun were found in a pond in Ramsbury, Wiltshire.

Halliwell pleaded guilty to killing Miss O'Callaghan but was not tried for a second murder after leading police to Becky Godden's buried body.

A police spokesman said: "Detectives are keeping an open mind as to why the gun would be in this location.

"Searches will continue over the weekend with fingertip searches and a specialist dive team from Avon and Somerset."

Miss O'Callaghan died from a single stab wound to the head. She was not shot.

The single-barrelled shotgun was discovered at about 16:00 BST.

The shotgun was found in the search area of a pond in Ramsbury

Det Supt Steve Fulcher, who quit his job on Thursday, did not caution Halliwell before he led detectives to the field in Gloucestershire.

Halliwell pleaded guilty to murdering Miss O'Callaghan and was jailed for 25 years in October 2012.

Her body was found after an extensive police search at the Uffington White Horse in Oxfordshire.

A police search has begun where the boots were found in Wiltshire, the second of which was retrieved from the water as reporters watched.

Christopher Halliwell pleaded guilty to Sian O'Callaghan's murder

Det Ch Insp Sean Memory said he believed that Miss O'Callaghan may have been murdered at the scene before her body was moved to Uffington.

He added they were hopeful they might retrieve other items belonging to Miss O'Callaghan that were not found in the original inquiry.

He said a bag, mobile phone and jewellery were among the items missing.

"This is an important find and we are conducting thorough and detailed searches of the area," said Det Ch Insp Memory.

"There are other items of Sian's property outstanding [and] we will be focusing the search for these items but keeping an open mind on what we might find."

He added that Miss O'Callaghan's family were being kept up to date with developments.

At another recent police search, in Gloucestershire, a piece of bone from Miss Godden's body and "other items" were found but police have not revealed what they are.

Sian O'Callaghan's boots were found near Ramsbury