Her latest movie may be subtitled I want to Believe, but a pregnant Gillian Anderson looked thoroughly unbelievable at its London premiere this week.

In a halternecked black and white print maxi dress, the actress, who turns 40 next month, wowed the crowd with her effortless style.

It was the second time this week that Anderson has received media eulogies for her wardrobe – snapped outside the Late Show with David Letterman in New York on Monday she was wearing a fabulously tall set of Fendi satin bow pumps.

However, with just three months before the birth of her third child, it wont be long before the US star is swapping high heels on the red carpet with comfort shoes in the house.

She told the BBC she felt "very pregnant" on the Leicester Square opening, adding she hoped the unborn child was "oblivious" to the hoards of screaming fans around her.

Other head-turning celebrities at the premiere included a bevy of 2007 Big Brother beauties, namely twins Samantha and Amanda Marchant and Posh Spice lookalike Chanelle Hayes.