Colin Firth's wife has stepped in to defend her husband after the actor's drastic weight loss sparked fears for his health, revealing the Oscar winner is just shaping up for a new movie role.

The King's Speech star has been pictured showing off a slimmed-down figure during an appearance at the Toronto International Film Festival in Canada, and the photographs have sparked a debate over his thin new physique.

Firth's wife Livia has spoken out in her husband's defence, insisting he has been in training for his role in Matthew Vaughn's upcoming spy action movie The Secret Service.

In a post on, she writes, "Re Colin's weight speculations: he has been asked to train 4 (for) Matthew Vaughn movie! Feeling fit but can't wait to expand again after Xmas!"