Independent retailers have continued to lead the way in the prevention of underage lottery sales, according to Camelot's test purchase scheme, Operation Child.

The independent sector came out slightly ahead of the multiples in tests held in 2007 with a first refusal rate of 94% compared with supermarket figures of 93%. As a trade channel, kiosks - which had a refusal rate of 84% - have the most work to do in preventing sales to under-16s.

While refusal rates for first visits were slightly down on 2006 figures, the 2007 results were still the second best results ever recorded. This year also saw record low figures for the number of stores requiring a third and final visit.

As part of the operation, retailers who fail a test purchase receive a follow-up visit and warning. If they sell illegally again on a final visit their terminal will be withdrawn. When sales are refused a congratulatory letter is sent to the retailer.

Camelot director of sales Steve Lucas said: "These results are encouraging, but we cannot afford to become complacent. We are determined to build on this success and achieve even better figures in 2008. We will continue to work closely with our retail partners to prevent underage play and to provide the support and training they need to be able to promote a responsible lottery in the UK."