The U.S. Customs and Border Protection has sent out disciplinary proposals for border agents on horseback accused of "whipping" Haitian migrants in Texas last year, an event that caused a firestorm among lawmakers in Washington, D.C.

Details of the punishments have not been released but CBP is expected to imminently announce the results of the administrative investigation, a source told Fox News.

The agency made headlines last year when agents were falsely accused of whipping the migrants along the Del Rio Sector in Texas. 

Images circulated on Twitter of the agents trying to block migrants from entering the U.S., and in one case grabbing a migrant's shirt. 


Haitian Migrants Del Rio border

U.S. Customs and Border Protection mounted officers attempt to contain migrants as they cross the Rio Grande from Ciudad Acuña, Mexico, into Del Rio, Texas, Sunday, Sept. 19, 2021. Agents involved in the incident are expected to face unspecified discipline.  (AP Photo/Felix Marquez)

The controversy escalated as some media outlets and Democratic lawmakers misidentified the agents’ split reins, which they use and twirl to control and direct the horse -- and falsely claimed the agents were using "whips" on the migrants.

Vice President Kamala Harris and President Biden also weighed in, with Biden increasing the pressure on the besieged agents by repeating the false claims of whipping, and also previewed what he hoped would be the outcome of the investigation.

"To see people treated like they did, horses barely running over, people being strapped – it's outrageous," Biden told reporters, making a whipping motion with his hand. "I promise you, those people will pay. There will be an investigation underway now and there will be consequences. There will be consequences."

The Office of Inspector General declined to press criminal charges against the agents and the investigation has since moved to DHS’ Office of Professional Responsibility.

Del Rio, Texas

United States Border Protection agents on horseback tries to stop Haitian migrants 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.  (Paul Ratje/AFP via Getty Images)

An announcement from the CBP is "imminent" regarding the findings of the investigation, the source said. 

Fox News' Adam Shaw contributed to this report.