Errors in the New South Wales police database that led to the wrongful arrest of more than 100 young people are set to cost the state $1.85 million.

An in-principal settlement has been struck after the Public Interest Advocacy Centre (PIAC) took up the cause of people wrongfully arrested for breaching bail conditions.

The Supreme Court has given claimants, some of whom were imprisoned and strip-searched, until October 9 to register for compensation.

PIAC chief executive, Edward Santow, said wrongful arrests had lasting effects on those taken into custody.

"One of the most serious things we can do as a society is to detain someone, and so we must only do that as a last resort," he said.

"When this occurs without any lawful justification, it's a very, very serious matter.

"One of our 14-year-old clients was arrested, handcuffed and strip-searched on three separate occasions over a two-week period. He was held in custody overnight each time."

Mr Santow warned there was no guarantee that the wrongful arrest of young people would not happen again.

Sorry, this audio has expired Background Briefing on RN explored the wrongful arrest of teens in NSW

"The problem is that there are no guarantees yet. So we're calling on the NSW Government to ensure that the IT system that the police rely on is absolutely watertight," he said.

The four-year-long class action was taken up when PIAC became aware of the arrests of children and young people because of inaccurate or out of date information on the NSW Police computer system known as COPS (Computer Operational Policing System).

NSW Managing Principal at Maurice Blackburn, Ben Slade, said the class action system in NSW had allowed young people to challenge the State Government.

"We are very pleased that the state has agreed to compensate these young people who were deprived of their liberty because of a computer problem," he said.

"There is no way vulnerable young people could possibly challenge such a well-resourced defendant as the State Government without the class action regime we have in NSW."

A spokesman for NSW Police said significant work had been done to correct the cause of the problem, namely the automatic transfer of bail variation details from the courts' database to that of the police.