A betting firm has been under the microscope after a sting operation was carried out to ensure gambling is not easily accessible to children.

The UK’s leading independent ID auditors, Serve Legal, visited every William Hill shop in the UK with undercover teenagers recently.

Results showed they were challenged for proof of age on 92.9 per cent of visits to the bookmakers in Walthamstow, Leyton, Leytonstone and Woodford Green.

Across east London the shops were visited on 141 occasions.

Nationally, the number of teenagers challenged was 86 per cent.

Matt Eastwood, commercial manager at London-based Serve Legal, said: “Nationwide William Hill are now on a par with supermarkets and convenience stores who have traditionally been the highest performing sector from facing checks from trading standards and police.

“The bookmaking sector has raised the bar significantly and improved performance in the past five years – in 2009 it was 50 per cent ID check rate and now they are in the mid 80s.”

Andrew Lyman, of William Hill, said: “We are delighted by the latest findings, but will not be sitting back and resting on our laurels.

“The staff in Walthamstow, Leyton, Leytonstone and Woodford Green are doing a very effective job in identifying possible underage visitors to our shops.”