There is no evidence to justify an inquiry into planning approval granted to a man at the centre of a row over donations to Labour, Hazel Blears said.
Mr Abrahams has said he never sought any favours from Labour
The communities secretary had promised to look into concerns about a business park proposed by Durham Green - a company controlled by David Abrahams.
But she said on Tuesday there was no evidence of "improper conduct" to justify a further inquiry.
Mr Abrahams donated £650,000 to Labour, under other people's names.
Those donations are being investigated by the Metropolitan Police.
Last week Tory communities spokesman Eric Pickles complained that a planning application for the business park had been made in the name of two intermediaries - and questioned why Highways Agency objections had been "suddenly and unexpectedly withdrawn".
In a letter to Mr Pickles, Ms Blears said: "I am of course happy to look into any claims of impropriety and improper conduct where there is any evidence to suggest that is needed.
"I have seen no such evidence in relation to the Durham Green case."
Ministers played no part in the deal, said Ms Blears
She said making planning applications in the names of companies and advisers was common and "a perfectly acceptable practice".
Ministers in her department had "played no part" in the Durham Green case, nor had the then transport secretary, Douglas Alexander.
And she said she had no record of any representations having been made to her department by Mr Abrahams or Durham Green over planning issues in the last three years.
Last year, Lib Dem-controlled Durham City Council awarded the 540-acre business park outline planning permission, despite initially being blocked by the Highways Agency.
An outline application covering 64 acres was withdrawn in November 2005 after the Highways Agency ordered the council not to approve the plan over concerns about extra traffic on the A1(M).
But the Highways Agency withdrew the objection for the latest plan, provided "appropriate planning conditions" were attached to the scheme.
It was one of the first schemes to get past a block on development from the Highways Agency because of over-capacity on the A1(M).
Mr Pickles had demanded a full cross-departmental inquiry to ensure decisions had not been "influenced" by Labour donors.
Durham Green Developments has only two directors - Ray Ruddick and Janet Kidd - the two employees of Mr Abrahams through whom he made donations of nearly £400,000 to Labour.
Mr Abrahams is not a director of the company, but it is registered at his home address in Gosforth, Newcastle.