'The Big Bang Theory' star Kunal Nayyar thinks the show will end in the next five years.

Kunal Nayyar at the Asian Awards

Kunal Nayyar at the Asian Awards

The 34-year-old actor has played Rajesh Koothrappali in the US sitcom since it began in 2007, with the show making him and his cast mates, who include Johnny Galecki, Jim Parsons, Kaley Cuoco and Simon Helberg, among the highest paid television actors in the world.

Kunal and his co-stars are contracted up until a tenth season and although he wants to portray Rajesh for as long as possible he believes that the show realistic only has few years left.

Speaking exclusively to BANG Showbiz at the Asian Awards in London, he said: "We have one more series in our contract, that's Season 10. Other than that I don't know. But I'll keep doing it for as long as they will have me.

"We could all have walking sticks doing 'The Big Bang Theory' Season 20. I think realistically there's less time left now than there was on the show before. Maybe it will go to 11, 12 or 13. I will do it as long as I can. But I think it is somewhere in that range."

Kunal feels very lucky to have starred on the show for several years and admits every time he gets a new script it feels like "Christmas morning".

He said: "You know I wake every day and get a script and I open it and it's like Christmas morning, because I'm just so excited to read it, the writers never let us down, they are such incredible story tellers and they have evolved these characters so beautifully. Sometimes you don't get the time to do what you want but we've had so much time and hopefully we'll have a little bit more. I just trust the writers."