A plastic seagull which made passers-by chuckle because of its Groucho Marx looks has been stolen along with 29 of his siblings.

Raoul, who wore glasses, a thick moustache and a big false nose, was a favourite with people walking past his perch in London Road, Brighton.

The bird was one of 30 £300 seagulls put up on phone boxes and other prominent places around the city to promote the Paramount Brighton Comedy Festival and every one has disappeared.

The festival has announced an amnesty on the birds and is even offering a reward of free show tickets for their return.

A spokesman said: "We are deeply shocked that there are people out there who would brutally kidnap this rare species of seagull.

"Raoul and his brothers have been lovingly cared for since we found them huddled in a lay-by near Swindon and, although they may look docile and a little plastic, in the hands of an untrained member of the public, they could rip your face clean off.

"We are all praying for their safe return, with as few casualties as possible."

Festival organisers are offering those responsible a one-off opportunity to redeem themselves and the first ten birds delivered to The Argus offices in Dyke Road by noon next Thursday will be gratefully received with no questions asked.

People who hand them in will receive a free pair of tickets to the Best Of The Fest comedy show at The Dome on Friday.

The seagulls were the latest publicity stunt from festival organisers who have previously turned the West Pier blue and used thousands of whoopee cushions to trumpet the arrival of the annual event.

A festival spokesman said: "We're thrilled to see how much the seagulls have caught the public's imagination.

"Not only are they synonymous with Brighton but they're also the perfect image for the Paramount Brighton Comedy Festival and we're already looking forward seeing a lot more of Raoul and his feathered friends at next year's event."