Class of 92 police probe: Nicky Butt's 50th birthday party, attended by fellow Man Utd legends David Beckham and Gary Neville, under investigation after 'head-butt' allegation

Several members of Manchester United’s fabled ‘Class of ‘92’ were at the event, which was held at the swanky Soho Farmhouse celeb haunt in Oxfordshire. David and Victoria Beckham own a lavish £12 million ($15m) estate not far from that venue.

Trouble is said to have broken out after one of the guests stepped outside and was confronted by a security guard after relieving himself against a wall – with the reveller in question reported to have landed a head-butt that left his victim requiring hospital treatment on a suspected broken nose.

A source has told The Sun: “The guard went to have a word with the guy causing offence and was then head-butted in the face. There was blood everywhere and people were shocked as the guard came inside with his face in a total mess. It’s the very last place you would expect to hear of that kind of behaviour going on. Soho Farmhouse is very upmarket and fashionable. This kind of incident is certainly not a regular occurrence there. The other guests and staff alike were all shocked about what happened. It ruined a lovely day.”

Thames Valley Police are now scouring CCTV footage, having confirmed their attendance and subsequent investigation. A spokesperson has said: “An assault at a business premises in Great Tew was reported to Thames Valley Police at about 9.15pm on January 24. It is alleged that a man assaulted a member of security. Thames Valley Police is conducting a thorough investigation, including taking a statement from and supporting the victim, obtaining and reviewing any CCTV available and taking witness statements. No arrests have been made at this time.”

The Beckhams, along with the respective families of Neville and Paul Scholes, are said to have left the party shortly after the incident in question. Ex-England international Butt, who forms part of Salford’s ownership team alongside his fellow former United stars, turned 50 on January 21 and invited friends for a day of celebration on January 24.