“Kenneth Martin was jailed in 1975 for seven years for his part in a child sex ring around the Playland amusement arcade in London’s Piccadilly”.


Kenneth Martin was also jailed for 13 years in 1989 during Operation Hedgerow, a police investigation into “Britain’s biggest child sex ring”. 


The Glasgow Herald Apr 8, 1989 (ocr)  13 years for sex crimes
A 65-YEAR-OLD sex offender whose catalogue of abuse against boys dates back 47 years was jailed for 13 years at the Old Bailey yesterday.  Kenneth Martin, who was convicted by a jury of 11 offences and pleaded guilty to a further four, was told by Judge Henry Pownall that he vvas a menace.
"You have done enormous harm, almost unimaginable harm,  to these boys because they did not for a period even know what they were sexually because of you."
Martin, who now walks with the aid of a stick, has committed offences against hundreds of boys and still has a "voracious" sexual appetite, said detectives who arrested him. "He needs a boy a day," one of them said.
Martin's first conviction for a sex offence against a boy was for buggery of a 12-year-old in 1942. Since then he has received a string of prison sentences, including a term in Dartmoor, for offences against boys. Martin was variously convicted of or pleaded guilty to offences including buggery, aiding and abetting buggery, and indecent assault. 
A police surveillance operation, code-named Operation Hedgerow and launched with the co-operation of Brent social services, led to the current trial and also the unearthing by police of what was described as Britain's biggest boys-for-sex ring. In February, at the end of a separate trial, four men, one of them a barrister, were jailed for a total of 34 years for involvement in that ring. The jury in the current trial heard that Operation Hedgerow began with a complaint from a 10-year-old boy.


Martin was jailed for 7 years in 1975 for his part in the child sex ring at the PLAYLAND  amusement arcade in Piccadilly.