This was revealed on Friday by the ruling party's General Secretary Obaidul Quader at an event in Gajaria in Munshiganj.
Quader said a party organising secretary and a joint secretary have been entrusted with the task to expose those responsible for Shimul's death.
On Thursday, a spate of violence broke out between rival factions of the ruling party in Shahzadpur.
He died on Friday while being shifted to Dhaka from Bogra.
With a number of controversies dogging the ruling party ahead of the 2019 general elections, Quader chose to read the events as a fallout of its leaders vying for dominance in the run-up to the polls.
But he said in doing so, they have become dependent of external 'sycophants'.
Speaking on the issue of errant party leaders, he said, "We are looking into the issue seriously. The prime minister's directive in this regard is in place. Many have been called to Dhaka and cautioned. If they do not still listen, we shall take stern steps against them."