Rhys Ifans put his soiled underwear in a Royal Mail post bag as a prank.

The 'Notting Hill' actor - whose behavior has become increasingly erratic
since his split from Sienna Miller earlier this year - decided to play the
drunken prank at the headquarters of Britain's Q Radio after he had been
interviewed for the station.

After seeing a postman arrive, Rhys is said to have taken a pair of dirty
men's undergarments out of his pocket and hide them in the mailman's sack.

A source said: "Rhys and some friends were down in the reception being quite
boisterous. They had obviously been sinking quite a few drinks.

"He was particularly excited when the postman arrived. He went outside and
was singing 'Hey Mr Postman' and 'Special Delivery' and giggling to himself
manically."

"After handing out his letters, when the postman arrived back he looked
inside his sack and pulled out a piece of underwear. He looked as if he was
going to be sick when he saw them."

The furious postman reportedly stormed to the company's reception area
waving the offending item at arm's length.

A spokesman for Bauer Media, which owns Q Radio, said: "We did have an
unofficial compliant from Royal Mail about a rogue item in our post. But no
further action has been taken."

Sienna Miller gets into a taxi as she leaves the Groucho Club in London, England - (09/01/08).