Police in the U.K. have launched an investigation after an assistant to famed British artist David Hockney died on Sunday (17Mar13).

The 23-year-old man, named as Hockney's close friend and aide Dominic Elliott, was taken to a hospital from Hockney's home in East Yorkshire, England on Sunday morning in a serious condition but medics were unable to save him.

A post-mortem examination is due to take place on Tuesday (19Mar13) to establish the cause of death.

A spokesman for Humberside Police tells Sky News, "The 23-year-old man was sadly pronounced dead at hospital and the police notified. The circumstances of the man's death are not clear and officers are currently undertaking enquiries to establish events leading to his death.

"There were no signs of violence and a post-mortem examination is due to take place tomorrow which is hoped may provide further information."

Hockney, 75, was a major contributor to the 1960s 'pop art' movement and is considered one of the most influential modern-day British artists.