Sainsbury's staff have twice been caught selling alcohol to children in a police operation.

And Grove newsagents McColls is facing a review of its alcohol licence after it was also caught in the joint police and Vale of White Horse initiative.

During August, and again this month, police sent teenagers aged between 13 and 15 into 25 different pubs and off-licences across the Vale district.

Staff in seven served them alcohol, including Sainsbury's in Limborough Road, Wantage, which failed twice.

The news comes a week after the Vale Community Safety Partnership unveiled a pilot scheme in Wantage where children who are repeatedly caught with alcohol in public will be sent on an education workshop.

Teenagers also bought alcohol in The Lamb and the Blue Boar in Wantage, Mace/Danes in Drayton and Bellingers Service Station in Grove. Staff were fined £80. Further action will be taken against Childrey Village Store in High Street, Childrey, and McColls in Millbrook Square, Grove, where store supervisors were caught selling alcohol to the teenagers, said a Vale spokesman. The council spokesman said it had requested a formal interview with Sainsbury's and would consider further formal action if necessary.

A Sainsbury's spokesman said: "The test results in August were very disappointing as we take this issue very seriously. We have embarked on a major retraining programme for colleagues, and passed tests undertaken by trading standards officials this month and in May."

Peter Fowler, manager of Bellingers Service Station, Grove, said: "I do not make excuses, but I challenge anyone to estimate accurately the age of young people today."

The landlord of the Blue Boar said he was unaware the pub had failed the test.

McColls, in Grove, could have its alcohol licence revoked at a review meeting, at a date yet to be set, called by Oxfordshire County Council after the store's third test purchasing failure in August.

A spokesman for McColls declined to comment as did licence holders of Childrey Village Store and The Lamb in Wantage. The manager of Mace/Danes in Drayton could not be contacted.

Pc Darren James, of Wantage police, said: "We hope that the message is getting across to licensees and we will be continuing to carry out similar operations."