Sherlock series 4: Benedict Cumberbatch and Martin Freeman have to be 'persuaded' to return, says Steven Moffat

Both lead actors have packed schedules and 'don't need Sherlock anymore'

Benedict Cumberbatch and Martin Freeman will travel back to the Victorian Age in the next Sherlock special (BBC)

Benedict Cumberbatch has become such a big star since Sherlock began that its creators have to “persuade” him to return for further series.

The 38-year-old actor was nominated for an Oscar at this year’s Academy Awards and has a packed schedule of both film and theatre commitments.

“[Cumberbatch and co-star Martin Freeman] don’t need Sherlock anymore, so we have to persuade them to do it, which is fair enough,” showrunner Steven Moffat told Newsbeat at the Bafta TV Awards nominees party last night.

But before fans go into meltdown, both actors have signed on to a fourth series of the BBC detective drama – a move that pleasantly surprised Moffat.

“They are very serious about it, they do love it very much,” he said. “I didn’t think we actually thought we’d get a fourth series out of them.”

It is not unusual for actors to need coaxing into further series, something that Moffat does not think “unreasonable” and does with his Doctor Who stars too.

“I still sit with Matt Smith every time and Peter Capaldi and say – this is what we’re going to do,” he said. “They would like to know that we’ve got another bunch of stories that they would like to do. That’s a fair question.”

Filming has already wrapped on the next Christmas special, due later this year and set in the Victorian age, while series four is expected to air at some point in 2016.

Fear not, for Moffat does not think the end is yet in sight for Sherlock. “Sherlock can go on a long time because we just show up occasionally and do it. It’s like a reunion party every time,” he said. “I’m an optimist.”