Former Russian president Boris Yeltsin got so drunk during a visit to Washington that he was found standing outside the White House in his underpants trying to hail a cab to go and buy a pizza.

The following night he was mistaken for a drunken intruder when he was discovered stumbling around the basement of his guest house by secret service agents.

The drunken behaviour of Yeltsin, who was known for his fondness for vodka and died two years ago aged 76, were revealed by former US president Bill Clinton.