UKIP MEP Mike Hookem denies assaulting Steven Woolfe
The UKIP MEP involved in an altercation with Steven Woolfe has said he "categorically did not" throw a punch at his colleague.
Mike Hookem acknowledged he and his colleague had a "scuffle" in the European Parliament but insisted that he did not hit him.
"I am innocent," he told the BBC. "I never threw a punch. I never assaulted him. I will stand my corner."
UKIP's Steven Woolfe will be kept in hospital for a further 48 hours.
Thursday's incident is being investigated by UKIP and the European Parliament, where it has been announced the inquiry will be led by Conservative MEP Sajjad Karim.
There have been varying descriptions of what happened during what UKIP called an "altercation" and Mr Hookem told BBC Radio Humberside only he and Mr Woolfe knew precisely what went on.
Mr Woolfe, among the favourites to be the party's next leader, collapsed after their exchange and was taken to hospital.
The 49-year old had a precautionary scan which revealed there was no blood clot on his brain although he is to remain under observation for a further 48 hours in Strasbourg "as a precaution".
Mr Hookem said he was "shocked" by the MEP's hospitalisation in the hours following the incident but insisted it had been "blown out of all proportion" by the media.
He said the fracas took place in an "ante room" in the European Parliament following a "heated debate" among a wider group of MEPs as they questioned Mr Woolfe about reports he had had discussions about joining the Conservatives in recent days.
Mano a mano
He said Mr Woolfe had objected to remarks which he made. "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," he said.
"It's (what) people in Hull would term 'handbags at dawn'. A bit of a scuffle."
By BBC political correspondent Alex Forsyth
This row illustrates the deep-rooted divisions that have taken hold in UKIP since the general election.
In the broadest sense, they are between those who are loyal to Nigel Farage and his vision for the party - who credit him and his plain speaking, anti-establishment message for its success - and those who think that he asserted too much control as leader.
This group, among them some UKIP members who were former Conservatives, want broader policies.
That's the backdrop to this argument, MEPs were said to be angered that Steven Woolfe had considered defecting to the Tories.
UKIP is a party that has enjoyed enormous success in a short time but now it is wrestling with what it stands for, where it sits on the political spectrum and at the same time it is looking for a new leader.
Whoever that may be, their first great challenge will be to stop UKIP looking in at itself and concentrate on reaching out to voters.
He suggested Mr Woolfe's hospitalisation did not result from anything that he had done.
"I didn't push him. He fell back into that room onto an MEP that was stood just inside that room.
"Some of the MEPs helped him up. He stood straight up, there was no indication of him hitting his head on metal windows or anything else, he fell back onto an MEP."
When asked if he was worried if he would be suspended from the party, he said that if this happened Mr Woolfe would have to disciplined too and he hoped this would not happen.
He said Mr Woolfe has contacted him "to extend the hand of friendship" to him and he was now prepared "to shake Mr Woolfe's hand" if he wanted to.
While Mr Woolfe has not spoken publicly about the episode, the Daily Mail quoting him as saying Mr Hookem "came at me and landed a blow" after they left the meeting room.
He insisted he was not "bruising for a scrap" and that Mr Hookem had read his suggestion that they should deal with the matter outside "totally the wrong way".
Speaking outside the hospital on Friday, another UKIP MEP, Nathan Gill insisted his colleague was in "good form" and there was no danger to his health even though "it was at one stage touch and go".
Martin Schulz, the president of the European Parliament, wished Mr Woolfe a speedy recovery but suggested the episode would have consequences for the party.
He said: "The reported facts are extremely serious," and had been referred to the Parliament's advisory committee to be dealt with "as a matter of urgency" next week.
"It goes without saying that disrespectful and violent behaviour does not have a place in the European Parliament," he added.
Several leading UKIP figures have questioned whether Mr Woolfe can take part in a new leadership contest - triggered by the resignation of Diane James after only 18 days - following the episode.
But UKIP donor Arron Banks, an influential figure in the party and ally of Nigel Farage - who is interim leader after Ms James' exit - has expressed his continued support for Mr Woolfe.
"Of course he can," he tweeted, adding the public wanted "real people" not "phoney career politicians".