A US Border Patrol agent on horseback tries to stop a Haitian migrant from entering an encampment on the banks of the Rio Grande near the Acuna Del Rio International Bridge in Del Rio, Texas, on September 19, 2021.
CNN  — 

An unofficial challenge coin depicting the infamous image of an agent on horseback confronting a Haitian migrant is being investigated by US Customs and Border Protection’s Office of Professional Responsibility, according to agency spokesperson Luis Miranda.

The coin, which was on sale on eBay, is inscribed with phrases, like “You will be returned” and “Reining it in since May 28, 1924.” It’s unclear where the coin originated.

“The images depicted on this coin are offensive, insensitive, and run counter to the core values of CBP. This is not an official CBP coin,” Miranda said in a statement.

Challenge coins are historically collectable pieces of recognition that originated in the military but have become more popular with civilian agencies. They are often used to trade and given as tokens of gratitude.

“The CBP Office of Professional Responsibility (OPR) is investigating whether or not it is being sold by anyone at CBP, and will take appropriate action if so. The CBP Office of Chief Counsel (OCC) will also send a cease-and-desist letter to any vendor who produces unauthorized challenge coins using one of CBP’s trademarked brands,” he added.

Last year, during a surge of mostly Haitian migrants at the US southern border, photos surfaced of agents on horseback swinging long reins near migrants who had crossed the border near Del Rio, Texas – where around 15,000 migrants had amassed under the Del Rio international bridge.

The incident drew swift condemnation from senior Biden administration officials.

CBP’s Office of Professional Responsibility has been investigating the incident, though the results of the investigation have not yet been released.

CBP Commissioner Chris Magnus said Thursday that the coins anger him “because the hateful images on them have no place in a professional law enforcement agency.”

“Those who make or share these deeply offensive coins detract and distract from the extraordinarily difficult and often life-saving work Border Patrol agents do every day across the country,” he continued.

This story has been updated with additional details.

CNN’s Shawna Mizelle contributed to this report.