Complaints that Portland Public Schools' interim superintendent may have had an undisclosed romantic relationship with a subordinate have spurred the school board to hire an outside law firm to suss out the facts, according to a source who insisted on anonymity.

The turbulence is bad news for a troubled district beset with vacancies that has counted on Interim Superintendent Yousef Awwad to steer it out of problems during two stints in as its interim leader and as its permanent deputy executive.

The investigation into Awwad was first reported by Willamette Week.

District policy does not forbid employees from holding supervisory positions over people with whom they have relationships. But it does require supervisors to notify their direct boss or the human resources director if they have a romantic or sexual relationship with someone under their chain of command. The policy says the human resources director must make the call, "in light of all the facts," about whether one of the employees should be moved to a different job.

District spokesman Dave Northfield said Tuesday he does not know whether Awwad has dated a subordinate or, if so, whether, when or to whom Awwad disclosed the relationship.

Awwad did not respond to questions from The Oregonian/OregonLive Monday or Tuesday. But Willamette Week reported he denied any wrongdoing.

Complaints that Awwad violated policies by dating a subordinate first came to board members' attention in the spring, the source said. They resurfaced as part of a broader complaint this summer after Awwad ascended to the top job and three new board members were sworn into office.

At the time the first report was made that Awwad and the female employee had a relationship, Interim Superintendent Bob McKean was Awwad's direct supervisor and Sean Murray was the human resources director. Both have since left the district. Awwad is currently supervised by the school board, and a consultant is filling the top HR job on an interim basis.

McKean did not respond to a request for comment Monday or Tuesday.

The new board plans to hire an outside law firm to investigate Awwad's situation, the source said.

The school board met in a private session for about 20 minutes Tuesday to discuss a personnel matter.

School board chair Julia Brim-Edwards, who took office July 1, would not discuss the complaints. "We are going to deal with personnel issues in executive session," she told The Oregonian/OregonLive. "Any complaint the board receives we are going to take seriously."

Awwad rose within the ranks of Oregon's largest school district over the last year from chief financial officer to deputy chief executive officer. In July, he was tapped to take over when the contract of McKean, the interim superintendent, ran out and the district still lacked a permanent leader.

McKean told school board members would he deal with the complaint about Awwad last spring, the source said.

The school board has settled on a permanent superintendent, Guadalupe Guerrero, but is counting on Awwad to lead the district until Guerrero starts in October.