People are dying from extreme heat, which is also killing a large number of chickens and destroying tea plants
In 1999, Sirajul Haque Siru Molla was hacked to death in a village in the district's Kashiani Upazila.
On Thursday, Additional District and Sessions Judge Md Nazir Ahmed convicted 25 people of murdering the businessman.
Seventeen others have been sentenced to life in prison while three others got a 10-year jail term each.
Assistant Public Prosecutor Shahiduzzaman said the court also slapped a Tk 30,000 fine on each of the convicts who received life imprisonment.
The three, who received 10 years in jail, have been fined Tk 10,000 each.
All convicts, except for the seven fugitives, were in the dock when the verdict was delivered on Thursday, said the prosecutor.