HOUSTON --A veteran Houston police officer has been relieved of duty. Investigators say it stems from what he did during last week's Rodeo barbecue cook off. Former HPD Senior Officer Michael Hamby is accused of throwing a tear gas grenade inside a cookoff tent and he's now at the center on an internal investigation. Hamby was off duty and not in uniform when the alleged incident occurred. Rodeo officials say his actions could have seriously hurt people and they are not taking this lightly. A 30-year veteran of the Houston Police Department, Hamby is no stranger to the Houston Livestock Show and Rodeo. Up until Tuesday, he served as team captain of the calf scramble committee. But Tuesday morning, Hamby resigned. Friday night, he allegedly attacked the Fayette County Cookers tent with a weapon after an argument with some of its members during the barbecue cook off. "A tear gas canister was rolled under the flap or under the side of a tent, into one of the barbecue tents and several people exited that tent because of the tear gas," Houston Livestock Show and Rodeo Chief Operating Officer Leroy Shafter said. An eyewitness to the aftermath told us: "The smoke got me first. When it hit me, it choked me up. I started coughing. All of a sudden, I see a bunch of people come flying out of the tent." There were no reports of injuries, and guests returned to the cooker's tent about 15 minutes later. "This is a serious issue, and if in fact he did do it and it's proven that he did do it, he will not regain any committee status with the Houston Livestock Show and Rodeo," Shafer said. Though he's not facing any criminal charges right now, Hamby has been relieved of duty pending the outcome of an internal affairs investigation. Elected in 2004, Hamby was a long standing member of the police union's board of directors. He has since turned in his resignation. Neither the police union nor the union's legal counsel would comment. Hamby is denying the allegations. We contacted Hamby by phone to ask him about the allegations. He would only say, "Have a nice day," before hanging up.