Houston Controller Chris Hollins’ investor conference took place Tuesday without the  participation of key city officials after Mayor John Whitmore raised “pay-to-play” concerns sponsors.

At an Oct. 17 press conference, Whitmire said none of the previous eight investor conferences had corporate sponsors and that bond underwriting firms raised concerns about violating Securities and Exchange Commission rules.

“The investigation is in response to Controller Hollins soliciting $100,000 from vendors for a private meeting with him,” Whitmire said in a statement Tuesday. “It is the practice of the mayor’s office not to comment on active investigations. I did my job by bringing this to light.”

Hollins, who has called the mayor’s allegations “baseless,” told the inspector general’s office the same fundraising model was used for both events, according to the controller’s office. 

“The only difference is that the mayor controls the proceeds from the State of the City, while the proceeds of the investor conference flow to a non-profit donor-advised fund, where an independent body has exclusive spending authority,” the controller’s statement said.

The investor conference drew 110-120 professionals and highlighted “the positive investment potential of Houston,” Hollins’ office said Wednesday.

“The mayor’s support turned out to not be very important,” it added. “The conference still had full attendance and interesting panels.” 

Speakers listed in a revised agenda no longer included Whitmire or city finance, airport, convention center, and public works officials. 

Whitmire and Hollins, who both took office in January after winning runoff elections, have had tense exchanges over Houston’s structural budget deficit, as well as about a bond-financed settlement with firefighters and rating outlooks that were revised to negative from stable by S&P Global Ratings and Fitch Ratings.