Police believe they are close to solving the riddle of 13-year-old schoolboy Philip Cairns who vanished nearly 30 years ago.

The only real clue they ever had was the discovery of the youngster’s schoolbag in a lane near his home a week after he disappeared.

He was last seen at 1:30 p.m. on October 23, 1986, when he left his home in south Dublin after eating his lunch and was returning to school.

Now gardai strongly suspect convicted child abuser, former pirate radio station owner Eamon Cooke, murdered Philip.

Cooke died aged 79 at a hospice in Dublin on June 4 while still serving a 10-year prison sentence for multiple indecent assaults of two young girls.

Detectives, acting on vital information recently provided by a woman with links to one of Cooke’s former victims, interviewed him shortly before he died.

According to sources, he admitted knowing the schoolboy and having him in his car but he would not verify whether he knew the whereabouts of his remains.

Detectives are regarding as credible an account of a woman who was a nine-year-old girl when, she said, she saw Cooke kill Philip in his pirate station, Radio Dublin. She was too terrified of Cooke to report the attack for decades.

Detectives are discovering Cooke may have abused dozens, even hundreds, of children.

He is fast being compared after death to the BBC disc-jockey Sir Jimmy Saville who official reports in Britain say abused hundreds of children over 50 years.

Community activist Angela Copley, from Ballyfermot in Dublin, who supports survivors of childhood sex abuse, said she felt “very, very sorry” for the woman who says she saw Cooke kill Philip in the radio station. Copley added, “She was a child at the time. He instilled terror in his victims.”

Broadcaster Gareth O’Callaghan, in a Facebook post over the weekend, said he was related to the Cairns family. He said Philip had an interest in radio and “Cooke had promised him a visit to Radio Dublin.”

O’Callaghan, who worked on Cook’s pirate radio station in 1979, asked, “Can you trust the evidence of a then 9-year-old girl who has come forward to say that she saw Cooke hitting him on the head? She was vulnerable and upset. Can we trust her statement so many years later?”

Cooke is buried in Glasnevin, Dublin, in the same grave as his first wife Lena.

His second former wife told the Sunday World – which called her Sarah (not her real name) – that she divorced Cooke after years of abuse.

“I do know Eamon terrified people. Was he capable of killing someone? The answer to that is yes. He tried to kill me on a number of occasions,” she said.

Detectives are continuing inquiries to locate Philip’s remains and are cross-referencing DNA samples on the schoolbag with Cooke’s DNA.