Former Devon and Cornwall police authority chief Mike Bull faces an investigation by the Information Commissioner into an alleged breach of data protection rules.
The outgoing chairman, who has now been replaced by Police and Crime Commissioner (PCC) Tony Hogg, was reported by Exeter MP and former Culture Secretary Ben Bradshaw for allegedly "misusing" the police database and "electioneering" in the run-up to the PCC election.
Mr Bull had encouraged police officers to vote for the eventual PCC runner-up, Brian Greenslade, via two e-mails, sent to the work e-mail addresses of serving officers.
Mr Bull has denied any wrongdoing, saying he made it "clear as a bell" the e-mail was sent in his personal capacity.
The Information Commissioner (IC) has cleared Mr Bull of breaching privacy and electronic communication rules but he is to be quizzed in respect to a possible breach of the Data Protection Act.
In a letter to Mr Bradshaw, Paul Arnold, the IC's head of customer contact, said:"We will make further enquiries to establish the extent to which Mr Bull may have had access to information controlled by the police force when working via his domestic IT equipment or in a non-official capacity and the extent to which such practices are compliant with the DPA."