Camelot is to step up its test purchasing campaign from 7,000 to 9,000 visits a year when its third term as National Lottery operator starts in February.

Speaking at the Association of Convenience Stores' Responsible Retailing Forum, Camelot head of security Geoff Comb outlined its plans for the new term. "We're doing our best to ensure responsible play and want to educate retailers in preventing the purchase of National Lottery products by those under the age of 16," he said.

"Our retailer base has grown to 28,800 and we need to ensure we carry out test purchasing in as many locations as possible."

Camelot introduced Operation Child in 1999 to test retailers. If a first test is failed retailers are provided with training. If a further two are failed then the retailer's terminal is removed for at least three years. So far 11 retailers have lost terminals.

Comb said: "This year only 8% of test purchases resulted in a sale. There will always be human error but if we can keep the number below 10%, then we're doing a good job."