WASHINGTON — First, the Secret Service. Now, the Drug Enforcement Administration has been hit by a Colombian hooker scandal.

The Justice Department inspector general’s office is investigating at least three DEA agents in Cartagena, accused of hiring prostitutes, sources said.

The alleged DEA misconduct was unrelated to the incident involving the Secret Service at a Cartagena hotel while prepping for President Obama’s April visit.

But it was Secret Service agents being grilled about their wild night in Cartagena who ratted out their counterparts at the DEA, which launched its own probe.

The DEA has permanent offices in Columbia, including in Cartagena, where prostitution is legal.