Ukip MEP Steven Woolfe says that the injuries he suffered in a fight at the European Parliament prove that he was attacked by Mike Hookem.
"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," a statement released by Woolfe's team claimed.
"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."
Woolfe was taken to hospital after suffering two seizures during a vote in Strasbourg on Thursday (6 October).
Woolfe was alleged to have been confronted by Hookem – the party's defence spokesman, who served in the RAF and Royal Engineers – during a meeting earlier that day.
Hookem is understood to have said "a few choice words" to Woolfe about defecting to the Tories, according to the Guardian, before an altercation in which Woolfe is said to have hit his head.
Neil Hamilton, Ukip's leader in the Welsh assembly, said he had been told by colleagues in the European Parliament that Woolfe had "picked a fight with one of them and came off worse".
Hamilton told the BBC he had heard from a witness that Woolfe had bleeding on the brain, after he was knocked over and hit his head.
"He toppled over and hit his head on a glass window so it must have been quite a wallop," said Hamilton.
In an interview with Sky News, Hookem said that he did not hit Woolfe and posted pictures of his hands and Woolfe on Twitter, calling into question the existence of any bruises or abrasions.
A spokesman for Hookem said in a statement he stood by his version of events and plans to take legal advice.
The statement said: "Hookem stands by the statements that he made in various media interviews yesterday regarding Steve Woolfe.
"Hookem will now be seeking legal advice in relation to Woolfe's allegations and will be making no further comment at this time."
Sky News sources say there is evidence of bruising on Woolfe's face consistent with a punch and bruising on the back of his head consistent with a fall.
The same sources also claim there is photographic evidence of facial injuries taken immediately after the altercation and before Woolfe's seizure.