The CPS now has two months to decide whether or not to press charges.
It's been confirmed Lincolnshire Police has handed a file to the Crown Prosecution Service over allegations of election mis-spending.
It's one of 12 forces to have passed files to the CPS for consideration.
They centre on claims expenses for workers on the Conservative Party battle-bus during the general election 2015 should have been declared at a local level.
Lincoln's MP Karl McCartney has always denied wrongdoing and says he acted in accordance with the law and was told it a national party expense.
Yesterday a leaked email from the MP accused senior figures in the national party of trying to pass the blame on the issue.