Cameron Diaz is seeking "medical attention" after the sudden death of her beloved father, according to her What Happens In Vegas co-star Ashton Kutcher.

The actor is currently in London to promote the movie without Diaz after her father Emilio, died last week, aged 58.

And the 30-year-old expressed his concerns for Diaz at the movie’s premiere in the British capital on Monday night.

He told a WENN photographer, "Sadly she will not be joining us for the premiere as she has just lost her father and is under medical attention with stress at the moment.

"But she will be better soon."

Kutcher went on to thank the paparazzi for their concern for the heartbroken star, adding: "I will be telling her of your get well soon wishes and condolences following her father’s passing on."

On Saturday, Diaz was joined by ex lovers Justin Timberlake and John Mayer at a memorial service in California.