Former Chorley MP Den Dover will not face criminal charges over allegations of expenses misconduct while representing the Tory Party at Brussels and Strasbourg.
The decision by Hertfordshire police follows a two-year police investigation after he was ordered by the European Court of Justice to repay £345,000 of “unduly paid” claims in March 2011.
The 75-year-old, MP for the town between 1979 and 1997, was expelled from the Conservative Party in November 2008 after an investigation was launched into money paid to a family-owned company.
He stood down as a North-West MEP in 2009.
The cash has now been completely repaid. A spokesman said: “Hertfordshire Constabulary sought early investigative advice from the Crown Prosecution Service regarding an allegation of fraud relating to European Parliamentary expenses.
“On detailed analysis, the reviewing lawyer said that there was insufficient evidence of fraud and/or dishonesty.”
A CPS spokesman said: “At the request of Hertfordshire Police, the CPS gave some early investigative advice on this matter. No formal charging decision was requested and we understand that the police have now decided to take no further action.”
Mr Dover, who has always denied any wrongdoing, said he felt “exonerated”.