The procedure also raises questions about the city government’s transparency, he said.

“These kinds of actions raise questions about the motivation of the individual commissioners in potentially undermining a process without fully disclosing the basis for their recommendations,’’ Alfieri said.

A spokesman for the Portman group said the team had no comment on Weithorn’s allegation.

So did an attorney for the South Beach ACE group, Al Dotson Jr.

“It’s hard for us to respond to a rumor or an unspecific allegation,’’ Dotson said, while adding that Tishman team members were “very pleased’’ by the commission decision to stick with two bidders.

In December, the city commission endorsed a recommendation by city staff and a selection committee to have the two top-tanked bidders compete head-to-head in developing proposals for the project. Those are due around June. The teams are also expected to conduct a series of public meetings to seek residents’ input and vet ideas. The first is scheduled for Jan. 29.

A principal for the third-ranked team, David Edelstein, builder of the W Hotel on the Beach, argued strenuously during the December hearing that the commission was making “a mistake’’ by not including his group in the contest

Weithorn also complained the city has not adequately publicized the meeting schedule or the competition process, and won agreement of the commission to hire a public relations adviser to help the city do so.

Weithorn first raised the allegation of possible misfeasance at Wednesday’s commission meeting. A long memo written by an aide requesting the reconsideration made no mention of it. Neither did staffer Alex Fernandez or Weithorn in an exchange of emails and phone calls with a reporter on Tuesday.

Fernandez said Wednesday after the meeting that Weithorn did not learn of the allegation until recently. She did not notify the state attorney’s office, however, because her source told her prosecutors were already aware of it, Fernandez said.

Weithorn on Wednesday declined to elaborate on the allegation, but said she felt duty-bound to bring it to the commission.

“I think the allegation is serious, but since it’s just an allegation, I have no proof,” she said. “The allegation is essentially that Gus made contact to direct certain individuals to certain teams. Clearly, that’s inappropriate.”

Miami Herald staff writer Christina Veiga contributed to this story.