New Zealand PM John Key has launched an astonishing attack on LA Galaxy star David Beckham.

The Mirror reports Key was said to have insulted the Manchester United and Real Madrid legend while talking to schoolkids.

LA Galaxy star Becks visited the country to play in an exhibition match in December 2008, when Mr Key had just been elected.

The PM told pupils at St Hilda's Collegiate in Dunedin that his son Max had spent 45 minutes with Beckham, 37.

Key said the star was handsome and a very nice guy to spend that long with his son but is said to have joked he was "thick as bat s**t".

Beckham's agent refused to comment but a source close to the dad of four said if the story was true the insult was "pathetic".

The source added: "For someone supposedly thick, David has done pretty well to have become one of the world's most successful footballers and to be part of the bid to bring the Olympics to London.

"That doesn't sound like someone thick to me."