A prominent Minneapolis developer who used fake identities to deride a business rival in messages to City Hall has resigned as a commissioner of the city's public housing authority.

Steve Minn, a former council member, stepped down from the Minneapolis Public Housing Authority this Tuesday, a week after it was reported that he had violated no city ethics rules.

In a letter to the board, Minn said his mother is seriously ill and his wife has taken on responsibilities outside the development company they both operate, Lupe Development. "Therefore I am unable to give the MPHA the time commitment such an important responsibility dictates," he wrote.

The authority oversees the city's 6,000 public housing units, directing funding to cover everything from capital costs to security.

The accusations against Minn surfaced in an inch-thick stack of documents that Kelly Doran, a rival developer, delivered to council members and the mayor this January. Minn admitted the allegations were true and apologized.

They showed that Minn had e-mailed council members on several occasions, under fake names, to call Doran a "crook," "unethical," and "a bully." Doran was seeking public funding for environmental cleanup of a development site.

Minn also made many online postings using fake names on a popular e-democracy.org citizen message board.

In his resignation letter, Minn detailed why he chose this moment to leave the board.

"Having recently been exonerated from unsubstantiated accusations by a third party whom [sic] knows nothing of the MPHA's work, I feel the present moment is ideal for my voluntary departure, so a replacement Board member can be appointed," Minn wrote.

Minn served on the City Council from 1994-99. He was later a commissioner in Gov. Jesse Ventura's administration, though the Senate rejected his confirmation in 2000.

Minn did not immediately respond to a message seeking comment.