Irish actor Chris O'Dowd and his new wife Dawn Porter have been left frantic on their honeymoon after discovering their beloved cat has gone missing.

The stars married in August (12), but delayed their honeymoon until this month (Dec12) due to their busy schedules.

The couple is spending time in Los Angeles, but their relaxing trip was ruined when a pal informed them their pet cat Lilu had disappeared from their London home.

In a series of posts on her Twitter.com page, Porter writes, "My Siamese cat Lilu has gone missing. Seal Point (brown and cream). Kink at base of tail. Bermondsey area...

"Thank you! We are on honeymoon and my friend who is taking care of her is very worried and upset, as are we."

O'Dowd later re-tweeted the message from his account.