A tweet has been sent from the MEP's account with his statement and thanks to well-wishers. 

BBC News Channel

Politico reporter in Strasbourg Tara Palmieri tells the BBC that Steven Woolfe "appeared to be conscious and sitting up" a short time ago. 

She says that, for the time being, his collapse is "being treated as a medical incident, unless someone chooses to file a police complaint - but it seems like that will not be the case". 

She specifies that no formal complaint has been made to the European Parliament authorities or to the police. 

Press Association

A spokeswoman for the national police in France said: "No one has called us about this incident and so we have no plans to investigate it at this time. If someone decides to ring and make a complaint, we will of course follow it up." 

UKIP's press release also specifies, contrary to earlier reports: "There is no bleeding on the brain according to tests."

It says he did have two epileptic-like seizures and numbness on the left hand side of his body at 12.30, and did pass out, but that has now passed.

UKIP has released the following statement from Steven Woolfe, speaking from hospital in Strasbourg:

"The CT scan has shown that there is no blood clot in the brain.

"At the moment I am feeling brighter, happier, and smiling as ever.

"As a precaution, I am being kept in overnight  awaiting secondary tests to make sure everything in fine.

"I would like everyone to know that the parliamentary staff, the UKIP MEPs with me and hospital staff have been brilliant. Their care has been exceptional.

"I am sitting up, and said to be looking well. The only consequence at the moment is a bit of numbness on the left hand side of my face. "

UKIP sources have told the BBC there was a UKIP meeting of MEPs at 10am today. 

There was a "rumbustious argument" over whether Steven Woolfe had been talking to the Tory party. 

A verbal conflict arose and he went outside with another MEP. 

The other MEP took off his jacket and went outside the room and punches were exchanged. 

It is believed that he banged his head against a structure, a window or a wall but he got up. 

Steven Woolfe later collapsed, doctors were called and his wife was contacted. 

Doctors said he had two "epileptic-like fits" and they believed there was bleeding on the brain. 

He was taken to hospital where he has undergone further tests including a brain scan. He is conscious and his condition has improved in the last two hours.   

UKIP MEP Steven Woolfe is now conscious, UKIP sources have told the BBC. 

4 July: Nigel Farage announces he is stepping down as UKIP leader following the vote to leave the EU 

16 September: Diane James elected UKIP leader - Steven Woolfe did not stand after failing to submit the correct paperwork 

5 October: Diane James stands down 18 days after she was elected, saying she does not have "sufficient authority" 

5 October: Steven Woolfe confirms he will stand for the leadership 

6 October: Steven Woolfe is taken to hospital following reports of an "altercation" at the European Parliament in Strasbourg

Image source, PA

Steven Woolfe emerged from his place as UKIP's immigration spokesman to become a favourite for the leadership. 

The barrister, who is 49 today, is of mixed race and was born and brought up in the North, is regarded by many within UKIP as a candidate able to broaden the party's appeal beyond its southern and middle-class core. 

• The party's MEP for North West England since July 2014
• As candidate for Labour-held Stockport in 2015, Mr Woolfe finished third with 13.1% of the vote
• Born in Moss Side in Manchester, and grew up in Burnage as the eldest of a family of four. 
• Went to school at St Bede's RC Independent College and later studied law at Aberystwyth University before beginning his legal career at chambers in Inner Temple. 

Before politics, Mr Woolfe worked as a lawyer in the City of London and acted as counsel for hedge fund managers, as well as a consultant to financial institutions. 

He was embroiled in controversy earlier this year after it emerged he had admitted failing to declare a drink-driving conviction when he stood for a police and crime commissioner post. 

BBC News Channel

UKIP MEP Roger Helmer was in the meeting where the altercation in which Steven Woolfe is said to have been involved took place. 

He says that it was a "closed meeting and as such it's confidential" but did specify there was "a lively exchange of views - not uncommon in politics".

He also tells the BBC that when he tried to cross a walkway later in the European Parliament he was told "somebody had fallen".

BBC News Channel

BBC political correspondent Alex Forsyth says while it's been a "tumultuous time" for UKIP recently the news of Steven Woolfe's hospitalisation "comes as a surprise". 

She describes the MEP as a "popular" figure who is seen as perhaps "the party's best hope for its next leader". 

BBC News Channel

Brussels correspondent Damian Grammaticus says he hears that Steven Woolfe collapsed this morning inside the European Parliament complex although not in the chamber and he was subsequently taken to hospital in Strasbourg

He also tells the BBC News channel that he hears exchanges inside the party were "heated". 

Jo Coburn
Daily Politics presenter

Image source, PA

UKIP leadership hopeful Steven Woolfe has been taken ill at the European Parliament, a party spokesman says.

The MEP was taken to hospital in Strasbourg for tests and interim UKIP leader Nigel Farage has described his condition as "serious".

Mr Farage also said his collapse followed an "altercation that took place at a meeting of UKIP MEPs".

This story will be updated throughout the day.