Narayanganj Senior Judicial Magistrate Md Sayeduzzaman Sharif issued the order on Tuesday.
Police accused 35 individuals of the murders.
Among the accused are Nur Hossain, former Awami League-backed ward councillor of Siddhirganj, and three former officers of RAB-11.
Hossain is now in India awaiting deportation to stand trial.
Investigator, Detective Branch’s OC Mamnur Rashid Mandal submitted the chargesheet on Apr 8.
The court rejected a plea made by Selina Islam Beauty, the wife of murdered Ward Councillor Nazrul Islam, to reinvestigate the case.
She filed a no-confidence (naraji) petition against the chargesheet.
Nazrul Islam, lawyer Chandan Sarker, and five others were abducted from Dhaka-Naraynganj Link Road in Fatulla’s Lamaparha on Apr 27 last year.
Their bodies were found in the Shitalakkhya River three days later.
Investigator Mandal appealed to drop names of 16 people from the four cases filed by Beauty and Sarker’s son-in-law Bijoy Kumar Paul.
Beauty’s father Shahidul Islam alleged after the murder that Nur Hossain had given the RAB officers Tk 60 million to kill the seven.
A RAB investigation found involvement of its officers in the murders and Nur Hossain was behind it.
RAB officers Tarek Sayeed Mohammad, Arif Hossain, and MM Rana were arrested following a High Court order. They were expelled from the armed forces, too.
Nur Hossain fled to India, but was caught by the West Bengal Police in Kolkota.
An investigation committee led by Additional Secretary Shahjahan Ali Molla of the public administration ministry investigated the murders.