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's Steven Woolfe is in a "life-threatening" condition following an altercation with fellow party MEPs in Strasbourg.
Mr Woolfe, who turned 49 today, was taken ill after walking out on a vote at the European Parliament.
Woolfe, who declared on Wednesday his intention to run as party leader, was reported by Nigel Farage to be in a "serious" condition upon being taken to hospital.
Fellow leadership contender Raheem Kassem tweeted that he believed Woolfe was in a "life-threatening" condition.
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?