Piper says she now wants to go backpacking in India and Africa

"I'm not taking a penny from him," the 23-year-old actress told Radio Times. "I think that's disgusting."

Piper said she and Evans had "saved each other from our worlds of madness".

However, she admitted regretting that her parents heard about their wedding in Las Vegas in 2001 on the radio, rather than being told in person.

"We didn't speak for a while, although they understand now that at the time I had to be selfish," she said.

"I didn't want them to question it because in my head it was perfect, the first time in years I felt happy."

The actress is about to leave her role as Rose in Doctor Who, a decision a BBC spokesman said was taken "jointly" with Piper.

'Utterly grateful'

"The longer I stayed, the more scared I'd be of leaving because it's so comfortable and nice," she said.

"I'm utterly grateful for the whole experience, but you have to take care of yourself and do what you feel is right.

"We filmed in Wales for nine months and I didn't like being away from home [in north London]. I enjoy being domesticated, washing-up and cooking dinner for my boyfriend."

In the interview, Piper also admitted she had tried drugs as a teenager, "but it never became a problem".

"I had my head in the clouds, was mad, neurotic and self-destructive, a very different character to the one you see today," she said.

She also conceded the six-figure deal for her forthcoming autobiography might appear "ridiculous" to some.

But she justified it by saying: "Someone else is writing a book about me, so I'm going to tell my own story.