Detectives investigating the disappearance of NSW toddler William Tyrrell have arrested a 63-year-old man on the NSW mid-north coast in relation to a series of historical child sex offences.

NSW Police said investigators from the homicide squad attended an address at Bonny Hills, near Port Macquarie, about 1:30pm today and took Bill Spedding into custody.

He was taken to the Port Macquarie Police Station where he is being questioned by police about the alleged sexual assaults of two girls, aged three and six, in 1987 in Sydney.

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Officers from Strike Force Rosann stressed the arrest did not relate to William’s disappearance and investigations into that matter were continuing.

Mr Spedding has denied any involvement in the William’s disappearance from his grandmother’s home on Benaroon Drive at Kendall, on the NSW mid-north coast, in September last year.

The house is across the road from the Kendall State Forest, about 35 kilometres south of Port Macquarie.

Police believe he was abducted and hold grave fears for his safety.

Mr Spedding’s home and business was searched in January as part of the investigation.

The septic tank on the tradesman’s home was also drained and police seized a number of items from his home.

They also searched his pawn shop at Laurieton, where they seized items.

Last week police said they were also investigating the possible involvement of a paedophile ring in William’s disappearance.

“We have information that we’ve received in relation to a paedophile ring that may be operating,” Detective Superintendent Michael Willing said.

Anyone with information was urged to contact police through Crime Stoppers on 1800 333 000.