To his victims William “Bill” Lambert initially appeared as a mild-mannered grandad who had the best interests of young children at heart.

But his evil side has come to light revealing him as a sick paedophile who preyed on vulnerable young girls in a scandal that rocked Cheam 20 years ago.

Gillian Etherton QC, prosecuting, said Lambert chose young, innocent victims, deceiving them with bizarre lies.

He abused his position as a gravedigger through an ex-serviceman’s initiative to set up the Shed youth club at St Dunstan's where he preyed on the young girls in his private chambers.

The process to finally convict him started in 2009 when, following a counselling session, memories of one victim’s abuse resurfaced.

She reported the pensioner to the police who immediately launched an investigation.

Based on the first victim’s account, Sapphire detectives identified three further victims, one whom had emigrated from the UK.

The four women, who had not spoken to each other since their teens, gave strikingly similar evidence of abuse.

Lambert was eventually convicted of one count of rape, two counts of indecent assault and two counts of procuring girls to have sexual intercourse by deception.

Investigating officer Detective Inspector Neil Matthews said: “The verdict sends a clear signal the Metropolitan Police will pursue relentlessly those who commit these type of offences, even when a number of years have passed as in this instance.”

q The Crown Prosecution Service (CPS), which spent 17 years chasing Lambert through two trials, praised the victims in having the strength to give evidence.

During the trial victims spoke of “all sorts of harrowing emotions” resurfacing because of giving evidence.

Charian Caesar, CPS London lawyer said: “I hope they can take some comfort from Lambert finally being brought to justice.”