The telecom regulator blocked 12.75 lakh SIMs of six mobile phone operators during January-September last year as those were used in carrying international calls illegally.
Of the blocked SIMs, 61 percent were from state-owned operator Teletalk, according to an internal report of Bangladesh Telecommunication Regulatory Commission.
The telecom watchdog seized 20,593 SIMs in raids against illegal routing of international calls during the period.
The mobile operators blocked 83,819 SIMs by self-regulation; 41,679 SIMs used in illegal call termination were detected by two European sample testing companies.
Teletalk has been at the top in illegal call termination for several years though its market share is only 2.51 percent, according to the report.
BTRC officials said they informed the government and the parliamentary standing committee on the telecom ministry about the illegal practice of Teletalk.
Tarana Halim, state minister for telecom, said she asked the telecom regulator to take action against any operator involved in carrying international calls illegally.
“If the BTRC doesn’t take any action, it will have to accept responsibility for that,” she said at a press conference at her office on Wednesday.
Teletalk officials declined to comment on the matter. Md Faizur Rahman Chowdhury, chairman of the Teletalk board, and Gias Uddin Ahmed, its managing director, said they are yet to get the report.
Chowdhury, who is also the telecom secretary, said any negative report on Teletalk is easily leaked to the media, but this does not happen in case of other operators.
According to the BTRC report, 2.51 lakh Grameenphone SIMs and 1.44 lakh Robi SIMs were blocked during the period for illegal call termination.
If any SIM carries more than two hours of international calls on a single day, it would automatically be blocked, a directive says.
In the nine months, Teletalk blocked 3.57 lakh SIMs by self-regulation.
“Had Teletalk complied with the regulatory directive, the number of its blocked SIMs would have been higher,” a BTRC official said.
By self-regulation, Grameenphone blocked 2.47 lakh SIMs and Robi 1.39 lakh, according to the report.
BTRC seized 25,903 SIMs of Teletalk in 46 raids from January 2013 to August 2016, according to a report placed before the parliamentary standing committee on the telecom ministry earlier.
The regulator also fined Teletalk around Tk 14.89 lakh for illegal call termination in different cases; the amount is yet to be paid.