Mark Speight insisted he had nothing to do with Ms Collins' death

"The tragic loss of Tash has affected her family and me very deeply," he said in a statement. "Therefore I feel unable to commit to the next series."

Speight was arrested on suspicion of murder and supplying Class A drugs after Collins was found dead at the couple's London flat on 3 January.

He is no longer a murder suspect, but is on bail over the drugs matter.

The BBC said it accepted Speight's decision.

Joe Godwin, head of Children's Entertainment 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."