The National Board of Revenue yesterday asked commercial banks to provide information about financial transactions made by Opposition Chief Whip Zainul Abdin Farroque within the last five years.

A commercial bank official who spoke on condition of anonymity said that the Central Intelligence Cell of the National Board of Revenue (NBR) directed the banks to provide the information within a week in the interests of an internal investigation.

On the same day that a Dhaka court issued an arrest warrant against Farroque, another Dhaka court issued an arrest warrant against him in a defamation case relating to his "derogatory remarks" about the prime minister's son Sajeeb Wazed Joy.

On March 11 Farroque told parliament that Joy is involved in illegal Voice over Internet Protocol (VoIP) business that caused a loss of Tk 1,500 crore to the state exchequer.

A Dhaka court previously issued an arrest warrant against Farroque when other individuals lodged a case regarding the alleged defamatory statements.

The official said that the intelligence cell directed the banks to provide detailed information, including any of Farroque's closed bank accounts.

The Dhaka court issued the arrest warrant hours after AHM Aminul Islam, who identified himself as a political analyst in his case statement, filed the lawsuit.

On the same day the High Court directed the BNP leader to surrender before the trial courts within eight weeks.

Since March 11, eight cases have been filed against Farroque for his statement in parliament.

The cases were filed by local Awami League and Jubo League leaders in various courts in Dhaka, as well as Comilla, Noakhali, Bogra, Narail, Panchagarh, Laxmipur and Magura districts.

The letter from the NBR also directed the government not to harass Farroque or have him arrested in the next eight weeks.