The BBC has apologised for adding the sound of babies crying to its footage of the quins born at Oxford's John Radcliffe Hospital.

The five girls, delivered last Saturday, are the latest individuals to be drawn into the broadcasting fakery row.

The hospital distributed clips of the five babies and their Russian parents, who had defied the advice of doctors in Moscow that they should abort some of them.

While broadcasters such as Sky and ITN ran clips of the footage without the audio, the BBC's footage contained the sound of children crying, even though the babies had respirators in their mouths.

A spokeswoman for the Oxford hospital said: "There was no audio on our clip."

A BBC spokesman said the corporation should have left the footage alone.

He said: "We received the film without sound and on reflection we should have kept it that way."

The sound effect was later removed from the story.

The admission follows a series of broadcasting scandals over authenticity.

BBC1 Controller Peter Fincham resigned after a promotional tape for a documentary on the Royal Family implied that the Queen stormed out of a photoshoot.