Police are investigating an alleged scuffle involving friends of Sir Paul McCartney after the music star visited David Blaine's starvation stunt today.

A photographer for the Evening Standard claimed he was hit after he tried to take a snap of the star.

But Sir Paul's aides have told police that they were assaulted during the incident in the early hours of today.

The former Beatles star, who lives in Hove with wife Heather, had joined onlookers on the banks of the River Thames, near Tower Bridge, in London to take a look at the illusionist.

Blaine is attempting to spend 44 days without food in a clear plastic box, suspended from a crane.

But Sir Paul reportedly wanted to keep his visit low-key by avoiding having his photograph taken.

Photographer Kevin Wheal told the Standard he approached the star with his camera.

Mr Wheal said: "Then his friends, who seemed more like minders to me, grabbed hold of me and pushed my camera towards the ground."

Mr Wheal claimed Sir Paul pushed him in the chest with his open palm, swore at him and said: "It's a private visit."

A Scotland Yard spokesman said: "Shortly before 1am today officers near the David Blaine stunt show in SE1 became aware of a dispute between a group of friends, a photographer and other members of the public.

"Following the altercation, we have received two counter allegations of common assault.

"Walworth police are investigating and inquiries continue."

Sir Paul's long-standing publicist Geoff Baker admitted he "stupidly" tipped off the photographer that Sir Paul was present.

As a result, Sir Paul sacked him on the spot and stormed off in a rage.

Hours later the story had changed with Mr Baker again working as Sir Paul's publicist, after the musician told him he had been "joking" about firing him.

Mr Baker said: "Reports this was a fracas or anything other than a group of friends on a night out are heavily exaggerated."