Ukip MEP Steven Woolfe was punched in the face, new medical evidence suggests.
Sources told ITV News that "bruises consistent with a punch" were found by a team of independent experts.
Mr Woolfe was involved in an altercation with fellow Ukip MEP Mike Hookem in Strasbourg on Thursday.
Mr Hookem "absolutely" denies being responsible for Mr Woolfe's injuries and claims he acted in self-defence during a "scuffle".
Ukip leadership hopeful Steven Woolfe has "reached out the hand of friendship" to fellow MEP Mike Hookem.
Mr Woolfe realised things "did go too far" after the pair came to blows outside the European Parliament on Thursday - landing Mr Woolfe in hospital with a suspected brain injury.
Ukip MEP Nathan Gill confirmed that the 49-year-old has now been moved to a neurological department for a further 48 hours.
He stressed that Mr Woolfe's condition had improved and described him as being in "extremely good form".
"Steven has this morning reached out the hand of friendship to Mr Hookem, to Mike, and has realised that things did go too far in the MEP meeting", Mr Gill said.
He added that while it is "way too early" to consider whether Mr Woolfe will still run for party leadership, a "full and thorough" investigation into the incident will be held.
Sources told ITV News that "bruises consistent with a punch" were found by a team of independent experts.
Mike Hookem insisted he acted in self-defence during a "scuffle" with Ukip leadership favourite Steven Woolfe.
As Ukip and the European Parliament investigate the 'altercation' between Steven Woolfe and Mike Hookem, what could the repercussions be?