Mayor Ted Wheeler on Friday sent a letter to former Portland Police Association president Brian Hunzeker asking him to resign immediately from his role on the board of trustees for the city's Fire & Police Disability & Retirement bureau.

The April 2 letter follows Hunzeker's abrupt resignation on March 16 from his role as president of PPA, due to what the union described as a "serious, isolated mistake related to the [Portland] Police Bureau's investigation into the alleged hit-and-run by Commissioner [Jo Ann] Hardesty."

Since then, Wheeler has called on Hunzeker to immediately explain what "mistake" led to his resignation. Hunzeker has remained quiet. Separately, the city has begun three separate investigations related to last month's leak of false and damaging information about Hardesty. A fourth, broader cultural investigation of the Police Bureau is in the works.

Wheeler's letter says Hunzeker has served on the FPD&R board of trustees since 2016. The bureau provides pensions and aid for injuries to members of PPB and Portland Fire & Rescue.

"The position of trustee is one of great responsibility, and great trust," Wheeler wrote. "Given your recent resignation as President of the Portland Police Association and the basis stated in the announcement of your resignation, I believe it would be appropriate for you to also resign from your position on the FPD&R Board of Trustees. I request that you do so immediately."

The mayor's office says it is unable to comment beyond what's written in the letter, because Wheeler could be involved in potential discipline of Officer Hunzeker at some point.

It is unclear whether Hunzeker has submitted his resignation to the board yet following Wheeler's letter. Hunzeker did not respond immediately to WW's request for comment.

Sam Hutchison, director of FPD&R, did not respond immediately to WW's request for comment.