Penelope Wilton keeping schtum about Downton

Penelope Wilton has revealed she's been "sworn to secrecy" about the third series of Downton Abbey.

The actress, who plays Isobel Crawley in the hit TV show, said she is regularly approached by fans desperate to know what's in store as the show enters the roaring twenties.

"We've started filming but I can't tell you, I'm sworn to secrecy," she said.

"I get asked about it all the time, but I've practically signed the Secrets Act so I'm not allowed to say a word."

Penelope was joined by her Downton co-star Dame Maggie Smith for new film The Best Exotic Marigold Hotel, about a group of English pensioners who travel to India to stay in a seemingly luxurious retirement home.

The veteran star said making the movie couldn't have been more different from the ITV1 period drama.

"It was a much warmer experience! And, of course, it's a modern piece so I wasn't having to get into wigs and things. I did have a costume but it wasn't like Downton, I didn't spend hours putting a corset on," she added.