Notorious abuser Joseph McColgan, who received a 30-month jail sentence in the UK last week for child pornography offences, poses a real risk to children and could reoffend when he is released, according to one of the detectives involved in prosecuting the case.

McColgan, known as the "Beast of Sligo" for the decades of horrific physical and sexual abuse to which he subjected his children, was sentenced to a record 238-year jail sentence here in 1995.

He repeatedly raped his children and battered them with his blackthorn stick until they bled.

However, because the sentences ran concurrently, he served just nine years and moved to the UK when he was released from Arbour Hill prison in 2004.

But he was back behind bars last week after he was caught in possession of child pornography when he returned from Ireland, a trip he had taken without notifying police.

The 68-year-old was arrested and charged with 17 counts relating to indecent photographs of children and one of not notifying police that he had returned to Ireland.

Detective Constable Steve Harris of Devon and Cornwall police told the Sunday Tribune that McColgan would be subject to a supervision order when he is released.

"He is an extremely dangerous man," he said. "He's shown by his actions over the course of time that he won't really change. His previous offences were much more serious than the charges he faced here. But they show he still has an interest in children."

Harris noted that McColgan was an arrogant man who still could not accept his offending, and even owned a copy of the best-selling book written by his daughter Sophia about his abuse of her. This contained highlighted passages where he did not agree with her account.

Detective Constable Harris's comments echoed those of Exeter Crown Court judge Graham Cottle, who expressed concern that the 30-month sentence McColgan received last week was not long enough. With good behaviour, McColgan can typically expect to be released next year. "You are quite clearly a very dangerous man but the current state of legislation does not really allow me to give weight to that fact," Cottle said.

"You are a danger to children and upon your release, I very much hope that you are supervised to the highest possible level by the authorities."