A top executive of the Service Employees International Union who led the push for a $15 minimum wage resigned Monday morning following an inquiry into his conduct toward women, which reportedly involved sexual relationships between several female staff.

Scott Courtney was the executive vice president of the union, but resigned.

"This morning, President Mary Kay Henry accepted Scott Courtney's resignation as an elected officer and member of SEIU," spokeswoman Sahar Wali said. "This comes a week after she suspended him from his assigned duties based on preliminary information that surfaced through an internal investigation launched to look into questions about to potential violations of our union's anti-nepotism policy, efforts to evade our Code of Ethics and subsequent complaints related to sexual misconduct and abusive behavior towards union staff."

Wali said the resignation would not end the investigation. "President Henry has taken additional steps to ensure that, across our union, all staff are respected, their contributions are valued, and their voices are heard," she said.

Buzzfeed News reported Thursday that "complaints about Courtney had been an open secret among women." It reported that seven current and former colleagues of Courtney said he was known for having sexual relationships with female staffers and subsequently favoring them for promotion. Two claimed that Courtney did not act on sexual harassment complaints by others under his supervision.

"As SEIU's organizing director over the past six years, Courtney helped lead the Fight for $15, sparking a movement that Slate has called 'the most successful progressive political project of the late Obama era, both practically and philosophically,'" Courtney's biography said on the SEIU website. He reportedly married a union staffer recently.

The union was the main group involved in staging protests and other events for a $15 minimum wage, according to its Labor Department filings. It poured at least $14 million into the effort in 2016. That includes $3.6 million to the Fast Food Workers Committee, the main group behind the "Fight For $15" movement, as well as nearly $9 million to various regional workers committees engaged in similar activism.