RIVERSIDE, Calif. -

Riverside County District Attorney Paul Zellerbach is under the microscope after video uncovered last week appeared to show him tampering with his opponent's campaign signs in Indio.

Now there are questions surrounding some of the district attorney's law enforcement endorsements.

Since several police associations want Zellerbach to resign and end his re-election campaign - we took a closer look at who's still supporting Zellerbach's campaign.

The D.A. came under scrutiny after the Indio Police Department launched an investigation to determine if he tampered with campaign signs belonging to his opponent, Mike Hestrin.

According to Zellerbach's campaign website several police chiefs in Riverside County endorse his re-election, including San Jacinto Police Chief Steve Mike, Temecula Police Chief Jeffery Kubel and Moreno Valley Police Chief Joe Ontiveros.

However, all three men told us via email that is not so.

Ontiveros said, "I have not endorsed anyone for political office.  Doing so would violate sheriff's department policy prohibiting employees from engaging in political activity or endorsing any candidate while in official capacity."

Kubel and Mike who also work for the sheriff's department more or less echoed Ontiveros' sentiments.  In emails they said they hadn't endorsed a candidate - and department policy forbids them from publicly backing political candidates.

We uncovered other inconsistencies when examining Zellerbach's endorsements.  His campaign lists Desert Hot Springs Police Chief Kate Singer and Blythe Police Chief Steven Smith as backing his re-election.  But both chiefs are retired.

Palm Springs Police Chief Al Franz confirms he did endorse Zellerbach, but in light of the pending investigation -- he wrote in an email -- "If the Indio Police Department determines that a crime has been committed and the case is submitted to the Attorney General's office for possible criminal filing, I will re-evaluate my endorsement at that time."

Cathedral City Police Chief Kevin Connor, who also endorsed Zellerbach, tells us his endorsement is not iron clad.

"I believe it is wise to wait until all available facts are known - and then based on a complete picture, re-evaluate my endorsement."

Beaumont Police Chief Frank Coe wrote: "I believe it is prudent to allow the investigation into the allegations to be completed and submitted to the prosecuting agency and a decision rendered by them before I make a determination to reconsider my endorsement."

Zellerbach's campaign manager, Dave Gilliard, told us he wasn't aware that sheriff's department employees were not permitted to make public political endorsements - and that the appropriate names would be taken off the campaign website immediately.

As for the two retired police chiefs, he said they had signed endorsement cards before their retirement.

Gilliard added, Mike Hestrin also lists supporters on his website who are not backing his campaign.