HOUSTON, Texas (KTRK) -- "We know nothing." That was Mayor Sylvester Turner's main message Wednesday morning during a city council briefing called in light of the mayor's senior aide pleading guilty to federal public corruption charges.
A heated discussion took place while ABC13 investigative reporter Ted Oberg asked Turner what the outreach looked like after William-Paul Thomas submitted his resignation letter on July 26.
ABC13's media partner the Houston Chronicle reported on Tuesday evening that Thomas pleaded guilty on July 25 to federal public corruption charges.
"When (Thomas) sent you the resignation letter, this is a guy you've met with three times a week for years, did you call him to say, 'Hey what's going on?'" Ted asked.
"No, I did not. He expressed retiring for medical reasons, and quite frankly, I can relate to that because your medical situation can change on a dime. I can personally attest to that," the mayor replied.
So, that's when Ted asked Turner if anyone at all on his senior team reached out to Thomas, who had worked for the city for 15 years.
Turner again pointed at the fact he is undergoing his own medical situation which has called for surgeries that he recently had to undergo.
"When he said he had chosen to retire for medical reasons, I respected that. I didn't reach out to him at that point. I intended to reach out but, quite frankly, I've been tending to my own medical situation. Now, if that was not the case, I probably would have reached out sooner. I did not expect anything else and quite candidly, I'm surprised in the revelation here because it is out of character," Turner said.
WATCH: Mayor denies having known about aide's corruption charge plea
Since that exchange, 13 Investigates learned the city's Office of Inspector General has opened an investigation into the bribery case that could implicate Houston Fire Department or city permitting employees. According to the city's website, the inspector general's office "investigates certain allegations of employee misconduct."
Thomas' sudden departure certainly stunned city hall, but there appears to be more than a personal reason for it.
Citing a source with direct knowledge of the situation, the Chronicle reports Thomas admitted to conspiracy to accept a cash bribe in exchange for changing a bar's classification to a restaurant, allowing the bar to stay open longer during COVID restrictions.
Court documents, while are listed as sealed, were obtained Wednesday by ABC13 through the court system.
The unsealed documents say a Houston restaurant and bar, along with another Houston bar and nightclub, knowingly conspired with Thomas around May 2020. The businesses were not explicitly named.
One of the businesses in question required a temporary certificate of occupancy to continue operating and was required to pass an inspection by the Fire Marshal's Office of the Houston Fire Department, documents say.
Thomas is being accused of exchanging text messages and phone calls with that company regarding its need for the certificate. That's when Thomas agreed to use his position in office to "exert pressure on other officials to pass" the company at inspection in exchange for money, documents say.
They also state that Thomas made calls to certain Houston Fire Department officials to ensure the company passed inspection. On or about May 12, 2020, the company was issued the certificate, documents say.
Things allegedly did not end there.
WATCH: City inspector general's office looking into Turner aide bribery case
In June 2020, the same business person reached out to Thomas again for assistance after the Texas Alcohol and Beverage Commission (TABC) shut down their restaurant. Under the city's COVID-19 restrictions, businesses designated as "bars" were not allowed to operate, while "restaurants" could remain operational.
The second company in question was designated as a bar, so it was unable to operate. The same business person asked Thomas to help expedite the permit so that the other company could reopen as a restaurant, and in exchange, documents say the business person would "take care of" Thomas "really good."
On July 6, 2020, that person offered Thomas $13,000 to have the necessary permit issued quickly, documents say. Thomas allegedly agreed, using his position in the mayor's office to "pressure other officials to grant the necessary permit."
According to documents, by July 10, 2020, the company was permitted to open.
On July 25, 2022, the day before his resignation, Thomas responded to a criminal summons at the federal courthouse, according to court documents and sources. He entered the guilty plea, was processed, and released on bond pending sentencing.
A city council member has weighed in. Councilmember Mike Kubosh, a Turner critic, met the report with little shock.
"Former Housing Director Tom McCasland said this mayor created a culture of corruption. This is further evidence of the corruption," Kubosh said in a statement to Eyewitness News.
Wednesday morning, Ted asked the mayor about McCasland's previous comments.
"That's unfair because you're dealing with something that no action has taken place. One person can make an allegation, and all of you jump to conclusions and take that person's word. Then what does that say about where we are in society, because there have been many people who have made allegations about other folk that turned out to be false," the mayor fired back. "I am not going to let you sit here and try to tie things together where there's no connection and no basis. That's poor journalism."
The following email from Mayor Turner sent to all city employees Wednesday, which ABC13 obtained, touched on the ethical standards expected of them:
"As always, I want to thank each of you for your hard work and dedication as employees of the City of Houston. This is a reminder that each and every one of us is held to the highest ethical standards as civil servants to the residents of Houston. Each of you are responsible for reviewing and becoming familiar with the City's Executive Orders ("EO") and Administrative Procedures (collectively "Policies"), which are available at http://www.houstontx.gov/policies/. All Policies are to be adhered to and followed to the letter. Please take the time to review E.O. 1-51, Solicitation of City Employees, and E.O.1-28, Executive Order Regarding Gifts, as well as the other Policies applicable to your job duties.
If you have any questions regarding Policies or procedures, please contact your department's Client Relations Manager or your department's HR liaison."
The reported corruption case is the latest federal interaction with the city of Houston.
The FBI served a search warrant on the Houston Health Department in February as part of allegations of improper use of COVID funds involving a marketing vendor.
And last month, the Department of Justice launched an investigation into the city's policies and practices related to illegal trash dumping and their impact on Black and Latino residents.