WASHINGTON  Top federal regulators say they were taken aback when they learned that a California congresswoman who helped set up a meeting with bankers last year had family financial ties to a bank whose chief executive asked them for up to $50 million in special bailout funds.

Representative Maxine Waters, Democrat of California, requested the September meeting on behalf of executives at OneUnited, one of the nation’s largest black-owned banks. Ms. Waters’s husband, Sidney Williams, had served on the bank’s board until early last year and has owned at least $250,000 of its stock.

Treasury officials said the session with nearly a dozen senior banking regulators was intended to allow minority-owned banks and their trade association to discuss the losses they had incurred from the federal takeover of Fannie Mae and Freddie Mac. But Kevin Cohee, OneUnited’s chief executive, instead seized the opportunity to plead for special assistance for his bank, federal officials said.

“Here you had a tiny community bank that comes in and they are not proposing a broader policy  they were asking for help for themselves,” said Stephen Lineberry, a former Treasury aide who attended the meeting. “I don’t remember that ever happening before.”