NDIS Minister Bill Shorten says the actions of a former minister he alleges intimidated public servants were foolish.
Mr Shorten said Liberal MP Stuart Robert had "inappropriately" made requests to high level public servants after media allegations surrounding his dealings with a consulting firm.
He said any requests from an opposition should go through the relevant ministerial office.
The Nine newspapers reported consulting company Synergy 360, owned by a friend of Mr Robert, claimed in leaked documents the minister met the firm about government contracts.
Parliament was told investigations had shown one of Synergy's clients Infosys had been awarded four contracts totalling $274 million to upgrade payment software within the Department of Human Services.
Mr Shorten told Sky News' Sunday Agenda program, "the emails are sufficiently detailed as to warrant an investigation".
"We don't have anything definitive but there's been plenty of smoke, so for the sake of the reputation of the Commonwealth we need to satisfy ourselves ... if there's anymore to it," he said.
Mr Shorten said Mr Robert's contact with public servants after the allegations surfaced was "definitely foolish".
"It seemed to me he was trying to extricate himself, which is understandable," he added.
But Mr Shorten said departmental staff weren't at the beck and call of former ministers and that requests for documents or information should go through the proper channels.
"Do things right, the best process is always the best protection," he said.
Mr Shorten was asked if the allegations were enough to warrant a referral to the national anti-corruption commission once it's up and running.
"Let's just get to the bottom of it," he said.
Mr Robert rejected the "implied imputation" of the media reports "in the strongest possible language".
"I reiterate that all departmental procurements were run with the highest levels of probity," he said on Thursday.
"I had zero involvement with this procurement or any other procurements and reject completely these accusations."
