Digital Transformation Agency representatives told senators in an estimates hearing on Tuesday their agency had not been contacted about repairing the troubled project to shift student literacy and numeracy tests online after states and territories abandoned it in April.

Its admission came as new DTA chief Gavin Slater conceded he attended a post-budget dinner at Parliament House without knowing it was a fundraiser for the Liberal party.

The rollout of online testing was left in disarray when the Victorian, Western Australian and ACT governments announced they would withdraw from a trial of the NAPLAN technology, after South Australia and Queensland ditched it earlier in the year.

DTA official Nerida O'Loughlin said the program was an Education Department matter and that responsibility for IT projects remained with government agencies implementing them.

Labor senator Jenny McAllister said Education's failure to involve the agency raised questions about its role.

"We've been talking about this for successive estimates and it has struck me that the role clarity about what the organisation is trying to accomplish has been a little deficient," she said.

Power failures, freezing, browser issues and broken internet connections plagued initial trials of the online NAPLAN tests, according to a report by principals.

The online test will be gradually rolled out over a three-year period, and about 10 per cent of schools were expected to take part in its trial this year.

DTA officials told senators it wasn't involved in remediating troubled IT projects and that it was up to agencies to contact it about problems.

Senator McAllister said that was a change in direction for the agency after it told an estimates hearing last year the community would expect the DTA to step in when programs hit problems.

Mr Slater said it was not the agency's role to take over projects.

"We're simply not resourced to do that, and I don't think that's the best use of our expertise," he said.

"I think it's really important that accountability for projects resides with what I would call the business owners.

"We have an oversight role now to play and if we feel there's an opportunity to get involved and assist we will do that but that does not entail taking over the whole program completely."

Mr Slater admitted he attended a post-budget dinner at Parliament House which was a fundraiser for the Liberal party after a friend who was a staffer for Coalition MP Steven Ciobo invited him.

He did not say who paid for his ticket although denied paying himself.

Mr Slater told senators he had been unaware it was a fundraiser for the Liberals but was receiving advice about attending political functions.

"It is fair to say I have a lot to learn about my obligations and I'm going through that process."

Departments have reported 56 projects costing more than $10 million and 294 business systems critical to operations to the DTA as it reviews the government's IT reform agenda.

However the agency is yet to calculate the total value of those projects and assess their level of risk.

The government spent $6.2 billion last financial year on IT while it committed $9 billion over coming years.