Children’s TV presenter Mark Speight has resigned from the CBBC show SMart, following the unexplained death of his fiancée.

Speight, 42, said he felt unable to return to work on the popular programme after the "tragic loss" of Natasha Collins.

Collins, a 31-year-old actress and presenter, was found dead in the bathtub at the couple's London flat on January 3.

After Speight discovered her body and phoned the police, he was arrested on suspicion of murder and supplying Class A drugs. Police are no longer treating him as a murder suspect but he must wait until next month to find out if he faces drug charges.

The presenter has insisted he had nothing to do with his fiancée's death.

Today, he released a statement explaining that he could not consider returning to co-host SMart with Kirsten O’Brien: "The tragic loss of Tash has affected her family and me very deeply and therefore I feel unable to commit to the next series of SMart, which is about to start filming.

"I do wish Kirsten and all the team all the very best."

A friend said: "Mark is absolutely crushed by what happened to Natasha and is unable to contemplate going back to work at the moment."

Today the BBC said it accepted his decision to resign after 12 years on the long-running show.

Joe Godwin, head of Children's Entertainment and executive producer of SMart, said: "The next series of SMart is just about to go into production and, given Mark's recent terrible loss, we completely understand his decision. Everyone at CBBC wishes him well."

Speight and Collins met in 1999 when they both appeared on the CBBC show, See It Saw It, with Collins playing the jovial court jester to Speight’s King.

She went on to present corporate videos and work as a model.

They became engaged three years ago.

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