Titas Gas has provided gas connections to about 500 companies over the last four years violating rules, ACC Deputy Director Ahsan Ali told the news agency.
Ahsan is currently conducting a probe into the graft allegations against Titas Gas officials.
The inquiry has also unearthed that some top officials of Titas Gas Transmission and Distribution Company Ltd were involved in the graft, he said. The officials had given gas connections to the private companies in exchange for bribes, he added.
"There are allegations that Titas Gas officials took Tk 2 crore bribe from each of the companies. Just think, how much money was illegally collected," Ahsan said.
The ACC official said nearly 15 top officials of subsidiary companies of the state-owned Petrobangla were quizzed during the probe.
"I have already questioned Titas Gas Managing Director M Nowshad Islam and Bapex Managing Director M Abdul Baki in connection with the graft allegations," he said.
On April 2 last year, the ACC also quizzed former MD of Titas Abdul Aziz, its former director (operations) Khalid Hasan and general managers Engr Mujibul Haque and Engr Fuad-ul-Islam.
On March 10, the Anti Corruption Commission (ACC) launched a probe into the graft allegations against Petrobangla Chairman M Hossain Monsur and 13 managing directors (MDs) of its subsidiaries.
The ACC sources said the 13 MDs swindled over Tk 200 crore while carrying out development works in the last four years.