Cameron Diaz and Prince Harry `become gym buddies`

After the 38-year-old actress is said to have bumped into the royal after joining an exclusive private members' gym in South Kensington, London, whilst filming new movie Gambit.

And a source told The Mirror that the two were quick to strike up a friendship, with Harry even inviting her to join him and his mates on a boozy night out.

'Since arriving in England, Cameron was adamant she would keep up with her strict exercise regime,' the insider said.

'Producers secured her membership at the ultra-discreet, £3,500-a-year gym – totally unaware Prince Harry was also a member.

'Since first clocking one another and saying hello, they have coincided visits on two further occasions.

'During the second one, they were pounding along on adjacent treadmills and Harry cheekily nudged-up Cameron's speed dial, suggesting a one kilometre race. Cameron agreed... and won.

'They have become pretty friendly – Harry even invited his new gym buddy out drinking with him and his Sloaney chums.'

Clarence House declined to comment on the report.