"Any findings in the probe into a terror attack in the last decade have got to give clues to the other attacks, as it was the same group that used the same weapons to kill members of the same political party," the Daily Star reported quoting an investigation official who preferred anonymity.
It said LeT sent 32 Arges grenades to Harkatul Jihad Bangladesh (HuJI) which were used in at least seven major terror attacks, six of them targeting the then opposition Awami League leaders including Hasina, while former Bangladeshi-born British High Commissioner in Dhaka Anwar Choudhury was the target of the seventh one.
"In carrying out the blasts, Harkatul Jihad al Islami had been aided by a powerful quarter, some of who were in state power (at that time)," the report said.
Investigators unearthed these while trying to get to the source of the grenade used in the killing of Awami League leader and former finance minister SAMS Kibria.
Officials concerned were not immediately available for comments on the report. But a senior official Criminal Investigation (CID) told PTI they are expected to file a chargesheet against the suspects of the most gruesome of the attacks, the August 21, 2004 attempt on Hasina when 24 people were killed.
The seven attacks killed 34 and injured over 400. Several Huji men have been convicted on charges of attempts on life of the British envoy while the outfit's chief Mufti Abdul Hannan and two leaders to death.
Bangladesh police three months ago said they arrested the suspected coordinator of the Pakistan-based Laskar-e-Toiba (LeT) along with two accomplices from a downtown hotel under an intensified anti-militant campaign.
Security officials earlier said they suspected that the LeT operatives were providing money to Bangladeshi militant groups and recruiting operatives to be trained in Pakistan as they were in close contacts with HuJI and Jama'atul Mujahideen Bangladesh (JMB).
Police and elite anti-crime Rapid Action Battalion (RAB) arrested some 20 suspected Pakistani and Indian nationals in the past one year for their suspected links to the Pakistan-based LeT as part of an intensified campaign against militancy.
But most of them were accused of carrying fake currencies believed to be used to carryout their activities in India.