Mr Williams added that it "maybe wasn't important in this case".

Mr Brown did not appear in court but is now on trial in his absence on charges of robbery and burglary.

Mr Williams told the court Mr Brown first targeted the Lamb legal chambers building after a door was left open to let people come and go for a legal function.

"A male is seen entering into the chambers and he rifles through a coat on the banisters and seems to pull something out of the pocket and goes upstairs," he said.

"He then comes back down the stairs and appears to place something back into the coat, something he has just taken."

Mr Williams said a lawyer who was at the function spotted Mr Brown and asked what he was doing and why he was there.

"She asked if she could help him and he said 'I'm the cleaner'," said Mr Williams.

The lawyer, who works in the building, knew this was not true as she knew the cleaner, jurors were told.

She went to get the real cleaner and Mr Brown "changed his story" and said he was looking for work as a cleaner, said Mr Williams.

"He was then seen leaving the chambers with a bottle of champagne or sparkling wine he was not seen with earlier," he said.