The complaint brought against Daventry's MP after claims he had used Parliament stationery for personal or political gain has been dropped.
Daventry’s MP Chris Heaton-Harris faced criticism last autumn after he wrote to universities on House of Commons-headed paper seeking information about the teaching of Brexit and the names of the professors involved.
A complaint was brought against Mr Heaton-Harris by Michael Foster because the MPs' code of conduct states that any use of public resources should "not confer any undue personal or financial benefit on themselves or anyone else, or confer undue advantage on a political organisation".
However, after an investigation and numerous exchanges between Mr Heaton-Harris and the Parliamentary Commissioner for Standards, Kathryn Stone OBE, the allegation was not upheld.
“The allegation investigated was that the member had misused House-provided stationery by writing to 120 universities seeking information about the teaching of European affairs (in particular about Brexit) and the names of the academics involved,” said the commissioner in her written summary.
“In the course of the inquiry, the member explained that the purpose of his request for information was to improve his own understanding of the issue, and that he might also publish some of the responses on his website so that his constituents might also read them.
“The member gave an assurance that the publication of any such material would be free of charge.
“He also gave an assurance that he would not share information obtained through this request with his political party.
“In light of those assurances, the allegation of a breach of the rules and of paragraph 15 of the code of conduct was not substantiated.”
During one of the exchanges between the commissioner and the MP, Mr Heaton-Harris wrote: "The letter was essentially a 'freedom of information' request to universities (and has been treated as an FOI request by many of them) asking for information to help me continue my ongoing parliamentary research into European issues.
"To give some context, before being elected to the House, I was a Member of the European Parliament for ten years and I immediately went onto the European Scrutiny Committee in this place and served on that until the General Election in 2015; so throughout my political career I have been continually researching European issues.
"Indeed, as a founding member of the Fresh Start group of MPs in 2011, the research I was involved in formed ideas around what a renegotiation within the EU could possibly look like.
"I regularly publish the results of my work when it is concluded, usually with the input of other colleagues, on my website."