UKIP leadership contender Steven Woolfe has been discharged from a hospital in Strasbourg after collapsing following an altercation at a party meeting.
Mr Woolfe left hospital on Sunday morning, with a UKIP spokesman saying he was now "focused on continuing his recovery".
He was taken to hospital on Thursday after an altercation at a meeting of UKIP MEPs at the European Parliament.
The fracas is being investigated both by the party and the parliament.
Alex Forsyth, BBC political correspondent, said Mr Woolfe left the hospital via a back entrance and was understood to heading out of Strasbourg.
A party spokesman said Mr Woolfe would not be making any further statements on Sunday.
The 49-year-old is among the favourites to be the party's next leader following the resignation of Diane James just 18 days after she was elected to the role.
Meanwhile, fellow MEP Bill Etheridge has announced he will stand in the leadership election.
He told BBC's Sunday Politics he would not be supporting Mr Woolfe's leadership bid, adding: "And yes, I will be standing."
Raheem Kassam, former leader Nigel Farage's chief of staff, has already declared he will stand for the leadership.
Mr Woolfe collapsed after the altercation had taken place at the MEPs' meeting over whether the leadership favourite had been talking to the Conservative Party.
Mr Woolfe had a row with fellow UKIP MEP Mike Hookem at the meeting, before the pair went outside together.
On Saturday, a spokesman for the UKIP MEP said medical examinations suggested Mr Woolfe had bruising on his face that was not consistent with just a fall or seizure.
Mr Hookem - who has admitted the pair had a "scuffle" - has since tweeted a photo of his "unbruised" hands, saying he did not punch Mr Woolfe.
Conservative MEP Sajjad Karim will lead the parliamentary probe.
Following his collapse, Mr Woolfe had a precautionary scan which revealed there was no blood clot on his brain.
Mr Woolfe's spokesman said on Saturday: "A team of experts independent of the hospital staff were called in to examine physical injuries to Steven's face, head and body that were inconsistent with just a seizure, or a fall as a result of a seizure.
"The team of experts also examined other pieces of evidence including clothing and images relating to those injuries.
"Their report will shine a different light on claims currently being made in the media."
But, he added: "I am innocent. I never threw a punch. I never assaulted him. I will stand my corner."
There have been varying descriptions of what happened and Mr Hookem has said only that he and Mr Woolfe knew precisely what went on.
Mr Woolfe objected to remarks which he made, he said. "He then stood up in front of everybody and said 'if it's that, let's take it outside of the room', I think his words were 'mano a mano'."
"When I walked in he approached me to attack me. He came at me, I defended myself.
"There were no punches thrown, there was no face slapping, there were no digs, there was nothing."
"It's (what) people in Hull would term 'handbags at dawn'. A bit of a scuffle."
Mr Woolfe has not spoken in public about the episode, but the Daily Mail quoted him as saying Mr Hookem "came at me and landed a blow" after they left the meeting room.
Another UKIP MEP, Nathan Gill, said there had been no police involvement and Mr Woolfe did not want any police involvement.
The row comes amid division in the party over its future direction following the vote for Brexit.
The party is split between those loyal to interim leader Nigel Farage and former Conservatives who support broader policies.
MEPs are said to be angered by reports Mr Woolfe had considered defecting to the Tories.