The Independent Police Complaints Commission is revisiting its investigation into Lancashire’s Police and Crime Commissioner.
The move comes despite the Crown Prosecution Service announcing it will not prosecute Clive Grunshaw over allegations about his expense claims.
But the IPCC is carrying out “further investigatory work” after a complaint about its initial investigation.
Last month Mr Grunshaw said he made “mistakes” in some of his expenses.
Former Conservative County Coun Sam Chapman, from Chorley whose Freedom of Information (FoI) request to Lancashire County council first prompted the scrutiny of Labour’s Mr Grunshaw, is said to have queried the IPCC’s investigation report, which has yet to be published.
The IPCC is understood to have found 37 incorrect claims and 28 occasions where Mr Grunshaw could have made a claim but did not.
The CPS said in January there was “insufficient evidence” any claims had been “submitted dishonestly” and 28 none-claims “suggests” no financial gain was sought.
An IPCC spokesman told the BBC: “The Independent Police Complaints Commission (IPCC) is to carry out further investigatory work into expenses claims made by the Police and Crime Commissioner for Lancashire following representations made after an announcement that no charges were to be brought in the case.”
Mr Grunshaw said he had received no indication from the IPCC that it was reopening its investigation.
He said: “The only correspondence I have received from the IPCC was to tell me they had delayed publishing the final report in order to make it “evidentially sound and properly balanced.
“The CPS concluded I had no case to answer and as far as I’m concerned that has drawn a line under Sam Chapman’s allegations against me.
“I believe Mr. Chapman is once again trying to score political points when it has already been proved his allegations against me were false.” T
Mr Grunshaw, who became Lancashire’s first Police and Crime Commissioner in 2012 after having served for four years as the chair of the county’s police authority.