The cause of beloved British funnyman Rik Mayall's death will remain a mystery for weeks after initial tests proved inconclusive.

The Young Ones star, 56, was found dead at his home in London on Monday (09Jun14) by his stunned wife Barbara Robbin, and coroner's officers carried out a post-mortem on Thursday (12Jun14).

However, the investigation has failed to provide enough clues to determine the cause of the tragedy and officials now have to extend the scope of their probe.

It could take several weeks until a conclusive result is announced.

A spokesman for West London Coroner's Office said on Thursday, "The post-mortem was done this morning. The tests have proved inconclusive, therefore tests are ongoing."

Mayall had suffered from epilepsy and memory problems following a quad bike crash that nearly killed him in 1998.