Benedict Cumberbatch has revealed he was left tongue-tied while doing a scene with Oscar-winning actress Meryl Streep.

The 36-year-old admitted he froze as he acted opposite Meryl in a big-screen adaptation of the Pulitzer and Tony-winning play, August: Osage County.

He said: "We had one scene around the table with Meryl and I just couldn't act. I was in awe of her. She is spellbinding to watch. She really is extraordinary. If you ever have the luck to watch her, she is fantastic."

Benedict was named best actor at the Broadcasting Press Guild for his performance in hit series Sherlock and the period drama Parade's End.

The actor said it was "exciting" to be a part of the ensemble drama, where he plays 'Little' Charles Aiken.

"It's a fantastic screen adaptation of a fantastic play by Tracy Letts, directed by John Wells and produced by George Clooney, all wonderful people," he explained.

"It's got an extraordinary cast - Meryl, Julia Roberts, Juliette Lewis, Ewan McGregor and Abigail Breslin. Chris Cooper plays my dad. It's really exciting. It's such a great piece and they're just such wonderful actors."

The actor - who will next be seen on the big screen in JJ Abrams' Star Trek sequel, Star Trek Into Darkness - admitted he is often getting flustered by working with big names. Benedict, who begins filming his third series of Sherlock within the next week, also said he was "starstruck" by Sir Christopher Lee when they did a Radio 4 version of Neil Gaiman's fantasy Neverwhere together.

"I get starstruck all the time. I did a radio play with Christopher Lee, and I was like, 'It's Christopher Lee!'. It was extraordinary to talk to that man. I was really starstruck by him," he recalled.

"I'm very new to all this so I'm still tongue-tied when I meet my heroes, which is nice because I still want to be in the audience. Not mine - because I hate watching myself - but I like to go to the cinema and the theatre when I get the chance."