First it was Secret Service agents and members of the military who were part of President Obama's security detail during his trip to the Summit of the Americas in Cartagena, Colombia, last month. Now, allegations of dalliances with prostitutes there have spread to the DEA.

The Justice Department's Office of the Inspector General is investigating possible misconduct by at least two DEA agents, federal officials told the Associated Press Monday. ABC News reported the same day that at least three agents are involved.

The alleged misconduct is unrelated to the Secret Service scandal, but evidence of it developed as the Secret Service investigated.  The DEA said it was making its employees available to be interviewed by investigators.

"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," a DEA spokesperson said in a statement. "DEA takes allegations of misconduct very seriously and will take appropriate personnel action, if warranted, upon the conclusion of the OIG investigation," the statement said.

Sen. Susan Collins, ranking Republican on the Senate Homeland Security and Government Affairs Committee said in a statement Tuesday that she had been informed of the allegations against the DEA agents on May 4, but had been asked to stay quiet until the agents involved could be returned to the US and questioned.

"It's disturbing that we may be uncovering a troubling culture that spans more than one law enforcement agency," Collins said. "In addition to the Secret Service scandal, we now learn that 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."

Twelve Secret Service agents have been fired or disciplined in the prostitution scandal, and 12 military personnel have also been implicated. Whether any DEA agents will take a fall remains to be seen.