Benedict Cumberbatch says Sherlock Holmes doesn't have sex - because he's more interested in crime.

The 38-year-old British actor was catapulted to global fame playing a modern version of the fictional detective in the BBC series and his portrayal has left fans speculating as to whether the sleuth is ''asexual''.

Speaking in the new issue of ELLE UK, Benedict insists his alter ego has to avoid erotic acts because relationships would get in the way of his investigations.

Pontificating on whether Sherlock would be good in bed, he said: ''He's asexual for a purpose. Not because he doesn't have a sex drive, but because it's suppressed to do his work. Cold showers, looking at a lot of dead bodies ... that'll do it for you.''

Benedict - who was shot by photographer Mark Horn for ELLE UK - is currently in a relationship with Sophie Hunter but he admits the dating game has become more complicated since he became famous.

Speaking about dating as a celebrity, he said: ''It's a really double-edged sword. You know, you discover why people find you attractive - in a relationship or a tryst - and if it's just to have a go on you or try you out, then I can smell that a mile off.''

With his career at a high with roles in films such as 'Star Trek Into Darkness', 'The Imitation Game' and '12 Years a Slave' as well as Sherlock, Benedict has started to turn his attention to having a family.

He said: ''I can imagine I'll look back at this point in my life and think: 'Wow that was really extraordinary.' But at the same time I hope I'm looking back and going, 'Oh, that was the moment I got on with life and realised things beyond myself.' Without using words like 'marriage'. 'children' and 'family' - although I have just used those words - put it this way, I hope I've got other people to look back with me at that point. I hope I'm surrounded by family.''

The full interview with Benedict Cumberbatch appears in the December issue of ELLE UK, which is on sale on October 30 as a print and digital edition. Visit www.elleuk.com for details.