John Chell has been tapped to permanently replace Jeffrey Maddrey as the NYPD’s chief of department after an explosive sex scandal led to Maddrey’s resignation. NYPD Commissioner Jessica Tisch

New York City Police Department Chief Jeffrey Maddrey resigned on Dec. 20 after an employee, Lt. Quathisha Epps, accused him of sexual misconduct, including coercing her into ‘performing unwanted sexual favors in exchange for overtime opportunities.

Federal investigators are now looking into allegations of sexual harassment and substantial overtime payments involving Jeffrey Maddrey and Quathisha Epps, a source familiar with the probe said.

NYPD Chief of Department Jeffrey Maddrey has resigned following a bombshell allegation of sexual misconduct on the job.

Investigators were on a top floor of NYPD headquarters last week searching for evidence in the tawdry sex-for-overtime abuse scandal exposed by The Post, sources said.

Disgraced former NYPD Chief of Department Jeffrey Maddrey shrugged off the sex-abuse accusations filed against him as an “office fling” — as aftershocks from bombshell allegations that he swapped overtime for sex continue to rattle the upper levels of the department,

The lawyer for Jeffrey Maddrey, the former top-ranking NYPD chief who stepped down amid charges that he coerced sex from a subordinate in exchange for $200,000 in overtime, acknowledged an affair with the accuser on Friday but said she had pursued him with racy texts,

Former NYPD Chief of Department Jeffrey Maddrey had a brief, consensual relationship with a "self-professed swinger" lieutenant who is now under internal investigation for her whopping overtime, according to Maddrey's attorney.