The source said House Homeland Security Chairman Peter King, R-N.Y., and committee investigators were "aware of this for some time," CNN reported Tuesday.
Three senators contacted by CNN confirmed the investigation of the DEA agents. Judiciary Committee Chairman Patrick Leahy, D-Vt., said senators learned about the inquiry about a week ago but were asked not to discuss it until the agents were removed from Colombia.
News about the investigation follows the prostitution scandal involving U.S. military and Secret Service agents who were sent to Colombia in April in advance of President Obama's trip to the Summit of the Americas. Several Secret Service members have been dismissed.
"It's disturbing that we may be uncovering a troubling culture that spans more than one law enforcement agency," Collins said in a statement Monday. "In addition to the Secret Service scandal, we now learn at least two DEA agents apparently entertained female foreign national masseuses in the Cartagena apartment of one of the agents."
"The evidence uncovered thus far indicates that this likely was not just a one-time incident," Collins said.
DEA spokesman Rusty Payne said the Justice Department's inspector general is investigating, CNN reported.
"The Drug Enforcement Administration was provided information from the Secret Service unrelated to the Cartagena hotel Secret Service incident, which DEA immediately followed up on, making DEA employees available to be interviewed by the Department of Justice's Office of Inspector General," Payne said. "DEA takes allegations of misconduct very seriously and will take appropriate personnel action, if warranted, upon the conclusion of the OIG investigation."
Collins and another senator told CNN one other Secret Service agent came forward recently and volunteered to his superiors that he paid a prostitute while in Colombia in advance of President Obama's recent trip. An aide to Collins said the Secret Service told her office the agent said he thought he was paying for a massage, not for a prostitute.