Self-professed gambler Apirak "Sia Po" Chat-anon was detained after showing up at a police station in Bangkok to be questioned about a shootout on Tuesday that resulted in two men being wounded.
Mr Apirak was later released without condition by the Thon Buri Criminal Court after posting 350,000 baht bail.
The 28-year-old and his brother, Khemmathat Chat-anon, 25, were accompanied by Santhana Prayoonrat, a former deputy superintendent of Special Branch Police, when they reported to Pol Capt Somkiart Kitprapanan, deputy investigation chief at Phasi Charoen station, about 3am yesterday.
Mr Apirak is accused of shooting and wounding two men in front of Saree Sauna & Spa on Ratchaphruek Road in the Bang Wa area, Phasi Charoen district, about 10.30pm on Tuesday.
He told police he was a regular customer at the massage shop, and he was there with three friends that night before the shootout.
Mr Khemmathat was said to have made an appointment with two rivals, identified as Tang and Tua, at a nearby shop for talks.
However, the talks broke down and Mr Khemmathat and about 10 friends went to the massage shop, Mr Apirak said, noting they were there to meet him.
He claimed a group of his brother's rivals then arrived at the massage parlour, and one member of the group pulled out a gun and pointed it at him, prompting him to run for cover.
More than 60 shots were fired, Mr Apirak claimed, noting he was not carrying a firearm.
He said that after the shooting, he and his brother filed a police complaint, asking Pol Gen Suchart Theerasawat, deputy chief of the national police, to examine CCTV footage.
He told police his group was outnumbered. But the duo was arrested on charges of colluding in attempted murder, illegal firearms possession, carrying it in public and firing shots.
Around 7am, police searched Mr Apirak's family home in the district and reported that they found nothing illegal.
The wounded men were brought to Siriraj Hospital. Local media said one was shot in the back, while the other was shot in the mouth.