The alert follows confirmation that a parrot in quarantine in Britain had the deadly strain of bird flu.

There has been an increase in Scarborough of parrots for sale and some are bought from the back of vans.

Founder member of the Scarborough and District Parrot Club Angela Furnish said parrots that had been brought into the country illegally or reared in an aviary were being sold to unsuspecting members of the public who thought they were getting a good deal.

She said: "The only way that avian flu will come into the country through parrots is if they are traded illegally.

"I have had to re-home eight of the birds. People have bought babies that are not tame birds and are quite dangerous. It's very unlikely you are going to get avian flu from parrots, but you never know if people are bringing them into the country illegally."

Experts have played down the threat to people from bird flu as it does not spread easily among humans.

But there are fears the H5N1 strain could trigger a flu pandemic if it mutates with a human flu virus enabling it to spread more easily.

Experts believe the dead parrot caught the disease while it was in quarantine with 216 birds from Taiwan.

All of the other birds that came into contact with the parrot have been culled.