Detectives who charged a then-suspect in the disappearance of William Tyrrell with historical child sex offences were "just doing their job" and acted on a tip-off to Crime Stoppers, a court has heard.
The State of NSW says William "Bill" Spedding was charged as part of a "professional, careful" investigation into allegations dating back to the 1980s.
When he was charged in 2015, Mr Spedding was also a person of interest in the Tyrrell case after the boy vanished from Kendall in September 2014.
Mr Spedding is suing the state claiming the charges, which he was ultimately cleared of, were a malicious attempt by police to gain leverage against him in the Tyrrell investigation.
The 70-year-old was accused of sexually assaulting two young children in Sydney's south-west in 1987, despite being cleared by police at the time.
Mr Spedding has never been charged as part of the Tyrrell investigation and denies any involvement.
Today barrister Adrian Williams, acting for the state, told the NSW Supreme Court detectives were just "trying to do their job" when they charged Mr Spedding.
Mr Williams said the allegations were renewed in a call to Crime Stoppers in January 2015.
"This wasn't something that the police actively unearthed to 'get' the plaintiff," he said.
Detectives took the matter seriously, he said, and would have been "rightly criticised" for dismissing the claims out of hand.
Mr Williams said it was common in the past for allegations made by children to be "ignored" because they were inconvenient.
Now police are expected to thoroughly investigate such claims, he told the court.
"What occurred was a professional, careful, moderate process," Mr Williams said.
"A failed prosecution is not necessarily, or even commonly, a malicious one."
The barrister said records of the allegations were "real and extensive" and were not "manufactured" by Strike Force Rosann detectives.
The court heard former top detective Gary Jubelin came into the Tyrrell investigation subsequent to Mr Spedding being identified as a suspect and the separate call to Crime Stoppers.
Mr Jubelin "took an interest" in the child sex allegations but did "nothing to initiate or maintain the prosecution"," Mr Williams said.
"Mr Jubeln's focus was the disappearance of William Tyrrell," he said.
Mr Spedding has claimed Mr Jubelin intimidated and threatened to "ruin" him during an unrecorded interview in 2015.
Mr Jubelin and other detectives are set to give evidence in the hearing before Justice Ian Harrison.
