A paedophile postman from Cornwall who used Facebook and Bebo to groom hundreds of children for sex has been jailed for eight-and-a-half years.

After creating at least eight fake online profiles, Michael Williams, 29, targeted youngsters he met on his post round, on school runs as a taxi driver, and in his role as secretary of a football club.

At an earlier hearing at Truro Court, Mr Williams admitted 27 charges of inciting sexual activity, grooming and distributing indecent images.

He also pleaded guilty to voyeurism and possessing indecent images. Devon and Cornwall Police have identified about 500 victims he groomed or abused but believe there could be up to 1,000 youngsters in total because hundreds are too scared to come forward.

Mr Williams, of Tresooth Lane, Penryn, worked as a postman in his home town, where he was regarded as cheerful and helpful. He befriended many people on his rounds – including youngsters.

But he would also pursue the children using social networking sites – sometimes using false names and posing as a teenager. Many victims were tricked into performing sex acts on a webcam but he convinced others to meet him in parks, on beaches and at his home, where he abused them.

Police found thousands of indecent images on his computer and it is believed he would secretly film children as they undressed on nearby beaches.

Mr Williams’s former employer, Royal Mail, said it suspended him as soon as the police informed it of the investigation. He was dismissed after his arrest in February. He was also former secretary of Falmouth Town Football Club.

Judge Paul Darlow said Mr Williams’s “deceit and corruption” had damaged hundreds of children – both boys and girls. “Every method employed by you was designed to exploit young children by the means you knew would be popular with them – Facebook, Bebo, MSN Messenger,” the judge said.