Detroit — The wife of Mayor Mike Duggan has filed for divorce.

Mary Loretto Maher's filing Friday in Wayne County Circuit Court comes nearly six months after the couple defended their marriage in response to the mayor being publicly challenged over his ties to a local physician.

In a joint statement, Duggan, 60, and Maher, 62, wrote "this painful decision has not been made lightly" and asked the public to respect their privacy.

"Life is a journey with many twists and turns," the statement read. "Today, a new chapter begins for the two of us. We have decided to divorce."

The mayor and city's dealings with a nonprofit are at the center of an independent investigation into a potential abuse of authority over whether preferential treatment was given to Make Your Date, which is dedicated to preventing premature births.

Duggan's relationship to Dr. Sonia Hassan, who heads the program, has been publicly questioned in recent months.

The mayor, when asked, has repeatedly declined to discuss it, saying "I'm never going to talk about my personal life."

In the Friday statement, Duggan and Maher said they have "had many serious discussions, have sought out guidance, but in the end, feel this is the best decision for both of us."

"We soon may not be a married couple, but we remain in close contact and we are first and foremost parents," they said. "We will forever protect and be present together in the lives of our children and grandchildren."

The pair concluded by saying "we will not comment further" beyond the statement.

"We will continue to be supportive of each other, of our family and of the citizens of Detroit," the statement says.

A divorce settlement conference for Duggan and Maher is set for Aug. 2.

Alexis Wiley, Duggan's chief of staff, said Duggan will continue living in the Manoogian Mansion, the official mayoral residence in the city.

Last month, Detroit's Office of Inspector General launched a review of the mayor and city's dealings with the program led by Hassan, which is run by Wayne State University.

The investigation came after the Detroit Free Press reported that the program received $358,000 in city grants and benefited from a fundraising campaign that a city official led at the mayor’s request.

The mayor has vowed "100 percent" cooperation with the investigation and said the assertions are "completely false."

The mayor has said the city never directed a cent to a nonprofit. The partnership, he said, was with the university directly.

Duggan's statement came despite an email reviewed by The Detroit News from Wiley in 2017 to Hassan, who is affiliated with Wayne State University.

"Dr. Hassan, I’d like to introduce you to Ryan Friedrichs. He is our chief development officer and the Mayor has tasked him with launching a large scale fundraising effort to Make Your Date. He’ll be in touch soon!”

University representatives have reiterated Duggan's stance, that the program has been handled by Wayne State from the beginning. The 501(c)(3), the university has said, was never activated and has never received or put out a penny.

Wayne State has said Hassan is a volunteer in her effort to lead the program and that it was launched based on research done at the National Institutes of Health's Perinatal Research Branch at Wayne State and Detroit Medical Center's Hutzel Women’s Hospital in which Hassan played a prominent role.

Businessman Robert Carmack, who is facing felony charges over a city land dispute and locked in a public feud with Duggan, has accused the mayor of bribery and infidelity with airplane banners and video footage.

Carmack hired a private investigator last summer to trail the mayor and capture his comings and goings including visits to a Novi condo.

The footage, displayed on a billboard truck outside City Hall, also captured a woman visiting the same location.

The incident prompted the mayor and his wife in November to defend their marriage and also led Duggan to convene a news conference to announce to the media that he'd asked the Michigan State Police to review whether Carmack's actions — allegedly in retaliation for the city's refusal to drop property lawsuits against him — amounted to extortion.

On Thursday, the Wayne County Election's Commission signed off on the language of a recall petition targeting Duggan over the investigation into whether favor was given to the nonprofit and his alleged relationship with Hassan.

cferretti@detroitnews.com