SIGOURNEY WEAVER'S appearance in Doc Martin was such an extraordinary cameo that even Martin Clunes himself couldn't quite believe it was happening. The actress fled Hollywood for a small part in the ITV drama – which is set in Cornwall - earlier this year after a small chance meeting with Martin on The Jonathan Ross Show last year. Martin, who plays the titular lead in the show, appears on Wossy's show again this weekend where he reveals it was thanks to Jonathan that Sigourney came to him for a part. “I came on here to plug Arthur and George and Sigourney Weaver was here who I’d never met," recalled the 53-year-old actor. "She said ‘Oh I’ve watched every episode of Doc Martin…’ "It turns out, she is best friends with Selina Cadell - they were students together - who plays Mrs Tishell, our chemist and so that’s why she’d been watching." By a stoke of luck, Martin was joined by his wife and producer of the series Philippa Braitehwaite, 51, when the Academy Award-winning star came running for a part. Martin added: "My wife, was here afterwards and Sigourney said, ‘Oh can I be in it?’ and she said, ‘OK alright’. "We wrote a part for an American tourist and thought let’s wait and see if she likes it… and everything fell into place and over she came with her husband, Jim, and she was brilliant, she was really nice, the crew were so excited, so excited, I fell off my chair twice!” Keep reading HERE at Express.