The clash at the European Parliament earlier this month between UKIP MEPs Steven Woolfe and Mike Hookem has been reported to the French police.
European Parliament president Martin Schulz said he had referred the “regrettable” incident after a probe.
The parliament’s advisory committee on conduct concluded the two men’s account of events “diverged substantially”.
Mr Woolfe was rushed to hospital after collapsing in the parliament later on the day of the incident.
Mr Schulz said he had referred the matter “given the seriousness of the reported facts and their possible criminal implications”.
Speaking in the European Parliament in Strasbourg, Mr Schulz said medical examinations carried out following Mr Woolfe’s hospital admission suggested his collapse followed a blow to the head.
Ukip’s Mike Hookem avoids suspension over brawl as French police called in
YORKSHIRE UKIP MEP Mike Hookem has avoided suspension from the party over the altercation which left former leadership contender Steven Woolfe in hospital.
Mr Woolfe quit the party and abandoned his leadership bid after the fracas with Mr Hookem in the European Parliament building in Strasbourg on October 6.
European Parliament president Martin Schulz has referred the “regrettable” incident to the French police “given the seriousness of the reported facts and their possible criminal implications”.
Statement from Mike Hookem MEP on Martin Schulz comments
UKIP MEP Mike Hookem said he had “no problem with any fair inquiry as it will demonstrate that I did not hit Steven Woolfe.”
“Ever keen to stir the pot, the European Parliament president Martin Schulz and the leader of the EPP Manfred Weber have made defamatory statements in the chamber today claiming falsely that I punched Steven Woolfe.
“I have responded to their disgraceful allegations by requesting that they repeat their allegations outside of a place they have parliamentary immunity.
“I’m afraid all I was met with was mealy words from a long-term bully pretending to be the tough guy but refusing to leave his plush tax payer funded feather nest and parliamentary privilege.
“If you have the guts, Mr President, to repeat your false allegations outside of the Hemicycle then yes, I will see you in court.
“Or you could spare us all the time and money and just apologise for your comments and your kangaroo court.”