Police spent millions of dollars on "dead duck" software and need to spend more to fix the severe problems now developer Wynyard Group has gone into liquidation.

Highly-touted software packages which cost police millions of dollars have severe flaws and been labelled a "dead duck".

At least $7.2 million was paid to the Wynyard Group for contracts which included two intelligence tools to help police investigate the most serious crimes and monitor child sex offenders in the community.

But the police will have to "invest significantly" more money to fix the problems - described in internal briefings as "severe enough to imperil the use of both solutions" - now the failed developer has gone under.

Wynyard was supposed to fix the defects at no charge under the contract, but went into voluntary administration last October.

Jade Software purchased the two applications from Wynyard, known as the Serious Crime Investigations & Intelligence Project and Child Protection Offender Register, the following month.

"Now that Jade Software has taken over, as they were not responsible for the defects, it is expected that they will charge police to fix them," according to a briefing released under the Official Information Act.

The budget for the 'Investigator' tool was exhausted, so there will be "no significant improvement to the quality or performance of the application unless police decide to invest significantly" with more money.

The third stage of the child sex offender register was approved by police but the project managers will instead request the funding be instead used for "fixing key defects that are in production first".

"Changes beyond defect fixing are, like with [Investigator], dependent on a police decision as to whether to invest significantly in the Jade product," concluded the briefing by Assistant Commissioner Jevon McSkimming, the chief information officer for the police.

In a statement to the Weekend Herald, McSkimming said "police are disappointed an external partner did not honour its obligations" after entering into a good-faith agreement.

He said the police would work closely with Jade Software to develop a plan to fix "Investigator" and submit a business case requesting more money to finish the job.

But Chris Cahill, the head of the Police Association, said the February briefing released to the Weekend Herald show the "Investigator" tool was a "dead duck".

"That February report shows the application is a dog and needs money spent on it ... it looks like a dead duck and spending the money for the fix isn't worth it," said Cahill.

"No one is using 'Investigator' anyway, it isn't being used at all ... I ran a homicide on it but it just frustrated all the staff, had to keep clicking and clicking to open up multiple fields, going back and forth.

"It certainly wasn't the game changer it was made out to be," said Cahill.

The $7.2 million paid to Wynyard was over the same five-year period wherein annual police budgets were frozen.

Wynard also supplied "Investigator" to the Serious Fraud Office, but the white-collar crime agency stopped using the product in 2016 with a year to run on the three-year contract.

"It became apparent that it was not compatible with some of the complex documents we use in our investigations," said a spokeswoman for the SFO.

"The Wynyard software couldn't resolve compatibility issues which were found between some of our forensic accounting documents once we started to use the system fully."

A SFO source said the software was nicknamed "Clicker" because of the number of times someone had to click the mouse before getting any result.