Chicago’s police chief was drinking with a woman for hours on the mid-October night officers found him sleeping behind the wheel of his SUV, according to two newspapers citing unidentified sources.

Mayor Lori Lightfoot fired Eddie Johnson on Monday for “ethical lapses”, weeks before he was set to retire.

She said an inspector general’s report, which has not been released, revealed he misled her and the public about the circumstances of the evening and showed “flawed decision-making”.

Lightfoot declined to share further details, citing an ongoing investigation and adding that her decision not to share details was out of deference to his family.

“While at some point, the inspector general’s report may become public and those details may be revealed, I don’t feel like it is appropriate or fair to Mr Johnson’s wife or children to do so at this time,” Lightfoot said at a City Hall news conference.

Johnson, 59, publicly blamed an issue with his medication, saying he felt lightheaded while driving home, pulled over and fell asleep. He also told Lightfoot he had “a couple of drinks with dinner” earlier that night. Johnson had been hospitalized during his three-year superintendent tenure for a blood clot and a kidney transplant.

However, the reports by two Chicago newspapers shed a different light.

The Sun-Times reported he was drinking for hours with a female member of his security detail at a downtown restaurant.

The Tribune reported that the inspector general’s investigation includes video showing Johnson drinking for hours with a woman at a Chicago Board of Trade building restaurant.

Johnson was found in his car by officers early on 17 October. The officers did not conduct any sobriety tests and let their boss drive home. It was unclear if they would be disciplined.

The Tribune reports that Johnson partially rolled down the window on his police vehicle, showed his superintendent’s badge and drove away.

Johnson, who has not spoken publicly since he was fired, was set to retire at the end of the month after three decades with the Chicago police department. The former Los Angeles police chief Charlie Beck, named as an interim replacement, took over on Monday.