Scott Morrison has confirmed he was approached by disgraced former NSW Liberal MP Daryl Maguire but insists it was not over a cash-for-visas scheme.
An initial sweep of the Home Affairs database did not uncovered any connection.
But the prime minister's office has confirmed a second search unearthed correspondence between the pair when Mr Morrison was immigration minister.
Mr Maguire contacted him on behalf of a constituent in 2014 to advocate for the deportation of a convicted child murderer.
"The then-minister responded factually to outline the process his department was already taking to review the matter," a spokesman for Mr Morrison told AAP on Wednesday.
Deputy Prime Minister Michael McCormack, whose federal electorate overlaps with Mr Maguire's former state seat, confirmed the pair had previously spoken about road projects.
"Yes I have had discussions," he told parliament.
Mr McCormack said their conversations had nothing to do with land acquisitions or the cash-for-visas scheme.
"N-O," he spelled out in response to questions from Labor.
The prime minister was on Tuesday asked whether Mr Maguire made any representations to him or the government about the visa scheme.
Mr Morrison, who was immigration minister at the time, left the possibility wide open.
"It has been my long established practice back when I was minister and certainly as prime minister, you receive representations from many people in the community, from those opposite included on many matters, including on those which the member has referred to," he told parliament.
"It is my normal practice for those matters through my office to be referred to the relevant department or my department for an appropriate response, and that is the practice I have always followed."
The cash-for-visas scheme dates to 2013 and has come to light during an ongoing NSW corruption inquiry.
Mr Maguire is accused of abusing his public office while serving as a state MP.
He once received thousands of dollars in cash to his taxpayer-funded office, with the money linked to securing Australian visas for Chinese nationals.
Mr Maguire has admitted making representations to immigration officials as well as federal politicians.
The scheme is being investigated by the Department of Home Affairs.
The department advised the prime minister's office an initial search of its database did not uncover any correspondence between Mr Maguire and Mr Morrison in his former role as immigration minister.
"Additional searches conducted in the PMO indicate the prime minister has not received any such correspondence in his current role," the spokesman told AAP.
Australian Associated Press