Aliens exist and they could be living among us, the first British astronaut in space has said.

Dr Helen Sharman, who went into space 28 years ago, said it is without a doubt that “all sorts of forms of life” are alive in the universe - but perhaps we “simply can’t see them” as they are so different to humanity.

“Aliens exist, there’s no two ways about it,” Dr Sharman told the Observer Magazine. “There are so many billions of stars out there in the universe that there must be all sorts of forms of life.

“Will they be like you and me, made up of carbon and nitrogen? Maybe not. It’s possible they’re right here right now and we simply can’t see them.”