TULSA, Oklahoma - A News On 6, Frontier investigation was the first to report on a decades-old practice of “buying rank.”

The practice centers on Tulsa Police officers paying a supervisor, anywhere from $20,000 to $50,000, to retire early.

After our story aired, many people asked how it was legal and if it happens anywhere else. We had the same questions and found only a few cases; and those do suggest the practice is unethical, at best.

A Tulsa Police officer told News On 6 and The Frontier there's nothing "morally wrong" with the practice of an officer paying a supervisor up to $50,000 to retire early, then taking the job.

But in 2008, a Texas sheriff heard about a similar transaction about to take place in his department and put a stop to it.

The Austin American-Statesman reported the sheriff denied the promotion - priced at $10,000 - because "it just didn't smell right."

The Ohio Ethics Commission ruled on a similar practice in 1997, saying, "the solicitation and acceptance of compensation from…[an] employee as an incentive not to perform his public duties by discontinuing his public employment...clearly violates [the law]."

Tulsa Democrats want the Attorney General to review the practice under the state bribery and income reporting laws.

A source said some officers issue 1099s to file the payments for promotion as gifts.

Marq Lewis with We The People Oklahoma is calling for further investigation.

"Just because things are legal doesn't make it right," he said.

The city charter says solicitations are prohibited.

The city ethics ordinance says city officials and employees cannot receive gifts that influence their duties.

Our partner, The Frontier, has more on this story on their website.