Bangladesh Nationalist Party (BNP) today demanded judicial inquiry to find out the nature of University Grants Commission (UGC) official's death in Rab custody.

Omar Siraj, 32, an assistant director of the UGC, who was arrested last month for his alleged involvement in leaking questions of medical college and university admission exams, died yesterday in the custody of Rapid Action Battalion.

"Judicial inquiry is needed to know exactly how Siraj died," BNP spokesperson Asaduzzaman Ripon demanded at a press briefing at the party's Nayapaltan office in Dhaka this afternoon.

People are being victims of custodial death but the law enforcement agencies usually claim the incidents as heart attacks, the BNP leader alleged. 

"The incident like custodial death is a matter of grave concern for us," he added. 

Siraj felt pain in his chest around 2:00pm yesterday at the Rab-4 office in Mirpur and was rushed to the National Institute of Cardiovascular Diseases, Rab said.

"There, he died of heart attack in the evening," Major Maksud Alam, deputy director (media wing) of Rab, told The Daily Star.

His body was then taken to Dhaka Medical College morgue around 10:00pm, morgue sources said.

"Rab and police officials brought the body," a morgue source said.

GG Biswas, officer-in-charge of Sher-e-Bangla Nagar Police Station, said Siraj was in the custody of Rab-4 and that he did not know exactly how he died.

Rab-4 arrested Omar Siraj and his accomplice Ishan Imtiaj Hridoy and storekeeper of Bangladesh Judicial Service Commission Rezaul Karim on September 18 from the UGC office at Agargaon in Dhaka.