An Irish man has suffered serious injuries after reportedly falling down stairs in Sydney’s east and becoming trapped until he was found five days later.

Donal O’Sullivan, 33, was reported missing by concerned relatives on Sunday after last being seen leaving the Tea Gardens Hotel in Bondi Junction the previous morning.

Police say he was found about 8pm (AEST) on Wednesday in a commercial building on Bronte Road in Bondi Junction.

He was taken to St Vincent’s Hospital with serious head and back injuries.

The Irish Echo reported that Mr O’Sullivan fell in a rarely-used stairwell in Easts Leagues Club.

His brother, Johnnie O’Sullivan, told the paper the caretaker found him suffering “some injuries” and dehydration.

“He managed to give his address and mobile number so we’re very relieved,” he said.