Benedict Cumberbatch is irreplaceable on Sherlock, according to the show's creator Mark Gatiss.
Gatiss revealed that the BBC series would not be able to continue without its leading man in the role of the fictional detective, adding that he and co-star Martin Freeman are vital to its success.
He told the Daily Mirror: "If Benedict went under a bus tomorrow it would be the end of the show.
"Benedict and Martin are our stars. We do three episodes a year and although people want more that's all we can do. They are so famous now it's difficult to get them."
The show's boss also recently responded to criticism that fans have to wait until 2016 to see new episodes of the show.
He explained: "Everyone wants to carry on doing Sherlock. It's a simple matter of schedules - particularly Benedict and Martin.
"They've become superstars, which is brilliant, but we all want to carry on as long as we can.
"There was suddenly a kind of outraged response that it might not be back until 2016 but that's precisely how long it always is. It's always two years! But we'd like to return soon, of course."