Police are to speak to Liberal Democrat leadership contender Chris Huhne over his complaint about Labour Party donor David Abrahams and his business dealings.
Durham Police said senior officers would be contacting the Lib Dem MP in the "near future" following a letter he sent to Metropolitan Police commissioner Sir Ian Blair.
Mr Huhne raised questions about the decision to allow a company controlled by Mr Abrahams to build a business park in County Durham.
A Durham Police spokesman said: "A senior officer from Durham Police is to speak to Mr Chris Huhne MP in the near future in regard to the contents of a letter he sent to the Metropolitan Police Service earlier this week."
The announcement comes after the Electoral Commission said it would refer the row surrounding Mr Abrahams' donations to Labour to the Metropolitan Police "for further investigation".
The row centres on £650,000 given to the party by the property developer under the names of other people.
Met Police Commissioner Sir Ian Blair said in a letter to Mr Huhne, who had called for a police probe into the secret funding row: "Matters relating to the donations to political parties are dealt with, in the first instance, by the Electoral Commission. The CPS and the Electoral Commission have been in dialogue with us (on Thursday afternoon).
"The Electoral Commission has now decided to refer matters to the MPS for further investigation.
"The next step is for us to receive and review their referral report."
