Suspecting conspiracy behind the two-day mutiny that left at least 73 army officers dead, Prime Minister Sheikh Hasina [Images] sought the assistance of the Federal Bureau of Investigation and the Scotland Yard to probe the massacre, as authorities said they have discovered another mass grave in the BDR headquarters.

Touhidul Alam, deputy assistant director of the BDR, who led a rebel delegation in talks with Prime Minister Sheikh Hasina, has been taken into custody while attempting to flee

the country, said Nabo Jyoti Khisha, the chief of Lalbagh police station in Dhaka where a case has been filed.

"The massacre took place under Alam's leadership. The rebels had accepted him as their leader," Khisha said.

The police claimed that they have gathered "enough evidence" against Alam and other conspirators of the two-day mutiny.

Among the 73 officers who were killed was BDR chief Maj Gen Shakil Ahmed. Mutilated bodies of his wife, Nazneen, and three other civilians were recovered from the mass graves and drains inside the BDR complex. Seventy-two army officers are still missing.

The home ministry put out a notice asking people to inform their nearest police stations immediately if they have any information about the absconding BDR personnel.

"We have already gathered enough evidence including the statements of survivors and the process is underway to collect more," said Khisha.

The Lalbagh police have filed cases against three other BDR deputy assistant directors and two lower rank soldiers of the paramilitary troops for leading the revolt, taking hostage, setting fire and hiding the bodies of the officials.

Meanwhile, President Zillur Rahman on Monday led thousands of mourners at a mass state funeral for the 49 army officers and one family member slain in the violent mutiny.

Air force jets flew overhead in salute at the mass funeral prayers held at the national parade ground in Dhaka on Monday. The army chief General Moeen U Ahmed was also present.

Hasina has already indicated that she plans to form special tribunals to try those who organised the mutiny, which she has described as "planned massacre" that may have received outside help.