Acting Chairman of the EFCC Ibrahim Magu and the Director General of the DSS Lawal Daura appeared before a Senate panel on Thursday to discuss the clash between their officials.
But their hearing was held behind closed doors.
Operatives of both outfits had clashed on 21 November, when personnel of the EFCC attempted to arrest former head of NIA Ayo Oke and former DSS DG Ita Ekpeyong.
The personnel of the anti-graft agency had arrived at the official residences of the former heads of the NIA and the DSS, located at numbers 21 and 46, Mamman Nasir Street in Asokoro, Abuja, to effect the arrest.
But they were resisted by the operatives of the NIA and DSS.
To this end, the Senate, on November 22, set up an ad-hoc committee to investigate the cause of the incident and report back to it.
The EFCC later said it had obtained two separate warrants from a court to arrest the former bosses.
Magu said, “We are not discouraged at all. The law must take its course, nobody is above the law.”
Ekpeyong had served as the head of the DSS from 2010 to 2015.
He had been invited by the EFCC for his alleged role in the arms scam involving former National Security Adviser, Colonel Sambo Dasuki (retired).
On his part, Oke was dismissed by the federal government over the N13 billion found in an apartment in Ikoyi, Lagos. The money was said to belong to the NIA.