Aguilera, Holmes sign up to 'Park'

Photorazzi / David Gabber

Christina Aguilera and Katie Holmes have signed up to star in a movie together, it has been revealed.

Aguilera, who is expecting to give birth within the next few weeks, and the former Dawson's Creek star will appear in family drama Humboldt Park.

A source said: "(Holmes) is trying to prove she can do more than fluffy popcorn movies." The insider added that by working alongside the singer she is showing that "she's willing to take risks".

Shooting is due to start in February.