Benedict Cumberbatch was initially considered by TV bosses to be not sexy enough to play Sherlock, it has been revealed.
The hit show's writer Steven Moffat revealed, during a talk at the Hay Festival, that the BBC had doubts about casting Benedict to star as the eccentric detective.
According to the Radio Times, Steven said that TV bosses also worried about casting David Tennant in period romp Casanova.
Steven told the audience: "They said of casting David Tennant as Casanova, 'Damn, you should have cast someone sexier'. With Benedict Cumberbatch, we were told the same thing. 'You promised us a sexy Sherlock, not him.'"
Both actors have gone on to become huge stars, and are considered heartthrobs.
Benedict has appeared in Hollywood films including Star Trek Into Darkness and Sherlock has a massive fan following around the globe.
After playing Casanova, David was cast as Doctor Who and has since starred in hit crime drama Boradchurch and its US remake Gracepoint.
Steven admitted that Benedict's international success as a result of playing Sherlock did have its drawbacks.
"It can be quite annoying if you're scheduling a damn show," he admitted.