DUP minister Nelson McCausland has accused the Assembly watchdog that monitors his department of a "witch-hunt" against him.
His criticism came after MLAs on the social development committee charged Mr McCausland with deliberately misleading them over allegations about public housing maintenance contracts.
But ahead of their report into claims made in a BBC Spotlight investigation, the minister launched a no-holds-barred attack that slammed the committee's investigation as "defective and partisan".
And the row intensified last night as the chair of the committee, Sinn Fein's Alex Maskey, condemned Mr McCausland's remarks as "contemptuous".
The minister had told the committee he met the Glass and Glazing Federation over specifications for a major double glazing program – but the programme revealed the meeting was with Turkington Holdings, a firm with links to his party.
Mr McCausland later apologised to the committee for "inadvertently misinforming" it, but committee members remain dissatisfied with his and officials' explanations. Their full report is expected in the near future.
But in a pre-emptive strike, Mr McCausland told the Belfast Telegraph: "This is a fundamentally flawed report which has been produced by a Sinn Fein-led committee which did not adhere to the high standards expected of a statutory committee.
"This is a defective and partisan report cobbled together to support a predetermined outcome.
"That is not an inquiry, it is a witch-hunt."
But Mr Maskey hit back: "I find the language being used here and the minister's attack absolutely contemptuous, and it is something the committee will want to discuss.
"From the very outset we have continued this inquiry in a very robust but fair way. It is ridiculous for him to suggest it has not been conducted to the highest standards.
"And while I chair the committee, it is not 'Sinn Fein-led'. Does he really think I can control Jim Allister (the Traditional Unionist Voice MLA who sits on the committee)? Does he really think I can control Stewart Dickson (Alliance)? Does he really think I can sit on and control Dolores Kelly (SDLP)?"
DUP committee member Sammy Wilson, however, strongly backed his colleague.
"Nelson McCausland never sought to hide the fact that he met with representatives of Turkingtons and that has been made clear on numerous occasions," he said.
"Unfortunately, a huge amount of time and effort has been wasted by the DSD committee."
The committee had agreed to set up their inquiry into the Spotlight programme's conclusions alleging political interference in the running of the Housing Executive.
The special edition also featured an interview with DUP councillor and Housing Executive board member Jenny Palmer, who said she was put under pressure by the party to change her vote at a board meeting.
There was political fury when the DUP moved last year to block an Assembly demand for a probe into claims Nelson McCausland abused his position and misled Stormont. Sinn Fein, Ulster Unionists, the SDLP and Alliance joined forces to agree a motion calling for an inquiry into whether the Social Development Minister breached the Ministerial Code of Office and misled MLAs. But the move was foiled after the DUP tabled a Petition of Concern. The debate came after DUP Lisburn councillor Jenny Palmer broke a two-year silence over allegations of political interference in the awarding of contracts.