Watch: UKIP MEP's furious row with EU President

UKIP's Mike Hookem has become embroiled in a furious row in the European Parliament with its president Martin Schulz.

The MEP threatened to sue Mr Schulz over claims the EU leader made that Mr Hookem had punched the UKIP MEP Steven Woolfe during an altercation in the parliament earlier this month.

Mr Schulz, who has reported both men to the French police, said in European Parliament on Wednesday that evidence suggested Mr Hookem had hit his colleague, something he has always denied.

The fight between the two UKIP MEPs ended with Mr Woolfe in hospital.

Mr Woolfe claims he fell backwards and hit his head after he was punched by Mr Hookem, but Mr Hookem has denied hitting Mr Woolfe during the row.

Mr Schulz told MEPs the "version of facts given by the two members diverged substantially" and the row appeared to have "happened in the absence of witnesses".

But he said the evidence suggested Mr Woolfe collapsed as a "result of an attack on the head".

In an angry exchange, Mr Hookem challenged Mr Schulz to repeat his claims outside the parliament, where he is protected from being sued for defamation, so he could take him to court.

He said: "Can you both leave this building where you don't have parliamentary privilege and repeat them so I can take legal action against you."

Mr Schulz responded to Mr Hookem, saying: "I would have no problem at all to see you in court and would be pleased to do so."

Interim UKIP leader Nigel Farage also interjected, querying whether the parliament buildings were "extra territorial" to French law.

Mr Schulz repeated that he had forwarded the case to the French police. He also said: "What I find regrettable is that as President I have to report that one man struck another, that's the real scandal here."

He had already told MEPs that on advice from the European Parliament Advisory Committee on Code of Conduct he had reported the matter to police and would decide how to sanction both men after the investigation.

UKIP has released its internal report into the incident, which said it was "impossible" to determine what happened as there were no eye witnesses.

But it concludes the altercation brought great shame on the men involved.

"The behaviour of both Mr Woolfe and Mr Hookem falls far below what we would expect from any member of our party, particular those who hold such high office," it said.

Commenting on the report, UKIP Chairman Paul Oakden said Mr Hookem "cannot be held principally responsible" for the incident or the subsequent press coverage.

"In light of this, a formal reprimand will be placed on Mr Hookem's internal record, to be considered in the event of a reoccurrence of any infraction which might cause damage to the reputation of the party," he said..

Mr Woolfe, who was previously seen as front runner for the party leadership, resigned last week because of the "infighting", which has been laid bare during the attempt to replace Mr Farage as leader.

Speaking after the incident, he said he suffered two seizures, partial paralysis and loss of feeling in his face and body as a result of the altercation and said he had made a complaint to police.

He said: "If it wasn't for the two doctors and the MEP that (were) there within minutes, things could have been a hell of a lot worse for me."

However, Mr Hookem denies punching Mr Woolfe and posted a picture on Twitter of his hands, pointing out there were no bruises.

Mr Hookem accused Mr Woolfe of "disloyalty" and holding talks to join the Conservatives.