The staff, who collect fines and work at courts and tribunals throughout the country, walked off the job at 1pm , protesting low pay rates.
Last week the workers staged two one-hour strikes and are also working to rule, or taking their work breaks together.
The strikes and the work to rule have been shutting down court sittings throughout the country, the workers' union, the PSA, said.
PSA national secretary Richard Wagstaff said the ministry would not address the fact an unfair pay system meant it paid its staff less than other public service workers.
On average, Ministry of Justice workers were paid 6.3 percent below the pay median for the public service. The ministry's 1200 court registry officers were paid 9.25 percent below the public service median for the work they do, Mr Wagstaff said.
Most court registry officers are paid between $39,600 and $46,600 a year. Their highest pay rate is $53,600. Most court registry support officers are paid between $29,500 and $35,000. Their highest pay rate is $40,000, he said.
Mr Wagstaff said the ministry had inflated the cost of closing the pay gap with the rest of the public service at $100 million.
"The ministry needs to begin addressing this underpayment and developing a transparent pay structure that ensures its workers are fairly paid for the work they do."
The ministry's general manager of district courts, Tony Fisher, was not available for comment this afternoon.
Last week he said "a realistic offer" had been made to the union, but it had declined to take to its members for ratification.
"The ministry has offered performance-based pay increases for staff effective from 1 July, 2010. Our preference is to reward performance, not time in the job."
The ministry wanted to resolve the dispute but could not afford to pay what the union was seeking.
