Mayor de Blasio said an investigation has found no criminal wrongdoing or intent to mislead on the part of a top administration aide whose boyfriend is a convicted killer and interstate drug trafficker.

Rachel Noerdlinger, chief of staff to first lady Chirlane McCray, has been in a relationship with Hassaun McFarlan since 2010 and the two have lived together for nearly two years, DNAInfo.com first reported last month.

Noerdlinger had been under scrutiny over allegations she filled out her official city background information form inaccurately by not mentioning she lived with McFarlan. A Department of Investigation probe cleared her, the mayor said Friday.

The mayor's press secretary Phil Walzak said "there was no intentional or deliberate attempt to mislead."

"We're talking about a mistake, with no evidence of any kind of deliberate or willfull attempt to distort," said Walzak. "I think if other folks made a mistake like this, the outcome would be the same."

But political analyst Basil Smikle said the controversy may linger because of the ongoing question of whether a friend of the mayor was getting special treatment.

"It could be any other city worker that's going to wonder, is she being given fair treatment?" he said.

Noerdlinger was at work at City Hall Friday but declined comment. Her attorney, Jeffrey Lichtman, has said her work was in no way affected by her relationship with McFarlan.

McFarlan has been arrested at least five times and was convicted in the fatal 1993 shooting of a teenager over a down jacket.

Two of the arrests occurred after the 36-year-old McFarlan began dating Noerdlinger, a former aide to the Rev. Al Sharpton.

McFarlan also allegedly referred to police officers as "pigs" on his Facebook account.

President of the Patrolmen's Benevolent Association Pat Lynch said when he learned of the relationship that Noerdlinger should never have been hired to work in the de Blasio administration.

"New York City police officers are not allowed to associate with known criminals," he said. "If we are, we get disciplined, and we should."

The mayor defended Noerdlinger at the time, saying she was in no danger of losing her job and that it would be "ludicrous" to fire someone over statements made by their boyfriend.

"I have absolute faith in her," de Blasio said. "I know what I value and she values the same thing. We need a close relationship between police and communities."

Walzak reiterated the sentiment Friday, calling Noerdlinger a "leader on social issues and civil rights and issues that matter to the administration," adding that her omission on the forms "obviously will be corrected."

Follow Andrew Siff on Twitter @andrewsiff4NY