Police have expressed "concern" about modified Kalashnikov assault rifles which fire ball-bearings.

Police fear the AK-74 assault rifles could be used for criminal activity and urged buyers not to display the guns in public.

Motorcycle dealer David Angel, of Burgess Farm, Middleton Cheney, near Banbury, who sells the famous Russian rifle for 289 apiece, said he was doing nothing illegal. The Kalashnikov AK-74 assault rifles are modified to fire ball-bearings and are sold as air rifles. Mr Angel said he would not sell to anyone under the age of 18

Mr Angel, who is the sole distributor of Kalashnikov motorcycles in the country, said: "I'm not doing anything illegal. If you want to rob a bank or building society, will you want to pay 289 for a Kalashnikov? You might as well go to a toy shop.

A police spokesman said: "We are certainly concerned about the proliferation of replica firearms because of the implications these have.

"Because of the sophisticated reproductions being sold, it is impossible to tell whether or not the weapons are real."

The spokesman said the police would assume the weapon was real if they were seen to be used inappropriately.