Tighter policies on city-issued credit cards are on the way after a Denver police officer was accused of using reward points from department purchases to load up on electronics for his own use.

The reward points were traded in for more than $1,000 worth of purchases at Best Buy, according to Denver Police Department officials.

The city’s Board of Ethics, in a new advisory opinion requested by DPD, unanimously agreed that an employee who tapped reward points in such a way would violate a general Denver ethics rule against using a city job for private gain.

DPD still is investigating the officer, whom officials declined to identify, to see if discipline is merited.

“Obviously, it was concerning enough for us to launch an internal affairs investigation and to ask for an ethics opinion,” Matt Murray, the department’s chief of staff, told The Denver Post on Friday.

He said the officer, whose job included many purchasing decisions, has been transferred to a new assignment.

City officials are learning from the case. The two-page ethics opinion, issued April 18, says neither the card agreement signed by employees nor procurement policies set rules about reward points. But the rules do bar purchases for “personal use.”

City Controller Beth Machann says a pending policy addition will cover the hundreds of employees granted city-issued purchasing cards.

“We will make a statement about use of reward point programs,” she said.

The upshot: any reward points earned from city purchases must benefit the city — not the employee with the card.

Aside from the DPD example, Machann said, she was not aware of any suspected abuse in other city agencies.

But she cited a potential risk: An employee who expected to benefit from reward points, she said, could direct city business to certain retailers.

During a Board of Ethics hearing last week, DPD finance director Jeannie Springer and Capt. Eric Rubin asked board members to weigh in on the officer’s case.

In her presentation, Springer provided little detail about the officer’s reward purchases, other than saying they were “valued at over $1,000.” Murray on Friday said he could not elaborate since the internal probe was underway.

The officer was among eight in DPD with a city credit card, Springer said.

But not anymore. Springer said she revoked the officer’s purchasing card “within an hour” of learning of the misused reward points. And DPD procedure has been changed, she said, to ensure that points earned on the cards are reserved for further department purchases.

The board specified in its advisory opinion that it wasn’t weighing in on frequent-flier miles that employees often earn for job-related travel. Government and private-sector employers often accept that practice because employees accrue miles in their names and on trips that take up significant personal time.

Jon Murray: 303-954-1405, jmurray@denverpost.com or twitter.com/ denverJonMurray