The jawans punished for irregularities in the BDR's Operation Dal-Bhat led the vicious killings during the Pilkhana mutiny on February 25-26.
However, the bloody revolt could be traced to the grievances nursed for years over alleged discriminations against the border guards, said sources close to the home ministry's high-powered probe committee and Criminal Investigation Department (CID).
The resentment among the rank and file for not being paid the allowances for duties in the Dal-Bhat programme only made things worse, they added.
"The killings were not part of the mutineers' original plan,” said a member of the home ministry's probe committee, requesting anonymity.
"They were the senseless acts of vengeance by the jawans who had been meted out punishment for stealing rice and wheat meant for the Dal-Bhat programme," he added.
Investigation sources said the February 25-26 carnage that left 75 people including 57 army officers dead was the third of its kind after the mutinies in 1991 and 1973.
Around 160 BDR men were disciplined for various irregularities and corruption including misappropriation of rice during the Dal-Bhat [rice-lentils] programme, which was introduced to rein in the spiralling prices of essentials during the caretaker government rule.
According to sources, a section of border guards misappropriated a huge quantity of rice and wheat on several occasions. They stole the staple goods while carting those to the BDR stores from the Local Supply Depot.
Sources in the CID, which is investigating the mutiny case, said a good number of detained BDR men who were penalised during Operation Dal-Bhat have admitted they were angry with the army officials in charge of the programme.
Asked, Abdul Kahar Akand, senior assistant superintendent of police (CID) and also investigation officer in the mutiny case, told The Daily Star, “Yes, some of the BDR men have admitted this."
Talking to The Daily Star yesterday, Major Gen Md Mainul Islam, director general of BDR, confirmed that the BDR men found to have been involved in corruption in the Dal-Bhat programme were indeed punished.
CID sources close to the cell monitoring the audiotapes and video footage said the BDR jawans flew into a temper as soon as the slain BDR DG Major General Shakil Ahmed began congratulating everyone on the success of Operation Dal-Bhat.
CID has so far arrested over 1,150 BDR men and 21 civilians in the mutiny case. Around 250 people including 15 civilians have been remanded for different periods.
Of the arrestees, 42 have already confessed to being involved in the bloodbath.
Kahar Akand said, "We are trying to complete the probe as soon as possible. However, we'd still need some more time for a better investigation."
Meanwhile, the government's probe committee is scheduled to submit its report on April 27. It has already been granted four extensions since formation.