Joanne Froggatt has admitted she was surprised by the strong reaction to her character's rape storyline in Downton Abbey.

The 33-year-old actress stars as lady's maid Anna in the hit period drama who was attacked by a visiting valet, played by Nigel Harman, and chose not to tell her husband Mr Bates (Brendan Coyle) what had happened to her.

Joanne confessed: "We all expected there to be a certain controversy when we tackled that subject matter, but I didn't expect it to be quite as controversial as it has been.

"I felt all along that we'd handled it very sensitively and I hope people see that as the episodes carry on. I am very proud of the way that Downton as a show has handled that, and I'm very proud of the fact they decided to tackle such an important issue.

"And the feedback so far has been very positive, so I hope people see it for what it is in the fact that Julian [Fellowes, the show's creator] really wanted to explore the emotional journey of those characters after the event. It's not just a shocking storyline to try and get viewing fiures. This happened and it still happens now and it's an important thing to tackle."

Mr Bates has now found out what happened to Anna after persuading Mrs Hughes (Phyllis Logan) to tell him, but he still does not know the identity of Anna's attacker, and he has vowed to find him and kill him.

Joanne admitted she was as frustrated as viewers with the fact that Anna chose to keep the rape a secret at first, but had learned that it was historically accurate for her to do so.

She explained: "This is something I wanted to know myself, because as a modern woman you want the character to tell somebody. Please tell somebody, and let the character get his comeuppance.

"But our historic adviser talked me through remembering being a woman in that time period, and all a woman had was her reputation and that was it. If she lost her reputation she lost everything - her job, her husband, her family.

"And in those days unfortunately the public still had the mindset of 'There's no smoke without fire', 'He's a man he can't control himself', all things we in this day and age find repulsive to think of. But for Anna there's so much at stake."