Besides the brothers, police have also taken one of their arrested business associates Debashis Kar on remand for five days.
Claiming that the remand was necessary to gather evidence against the brother duo, police had sought a ten-day remand.
Earlier, the police had taken the brothers on remand for 19 days in three phases in connection with their alleged involvement in the murder of their two former estranged associates Dipu Mallick and Omm Prakash Swain in November 2013.
He objected to registration of two separate FIRs in the incident arguing the cause, time and place of occurrence of the purported crime were same as claimed by the police.
The High Court had reserved its verdict on the issue after completing hearing on it on Monday.
The siblings Sushant and Sushil were arrested on January 29 for their alleged involvement in abduction and murder of their estrantged associates.