The Economic and Financial Crimes Commission (EFCC) has condemned the Tuesday siege by the Department of State Services (DSS) on its Lagos office, describing it as shocking.
The DSS operatives reportedly prevented officials of the anti-graft agency from gaining access to their office in Ikoyi, Lagos.
This was however denied by the DSS, claiming that the incident never happened.
The two organisations have shared the office which was the headquarters of the defunct National Security Organisation (NSO), the precursor to DSS, for about 20 years.
There is said to be an ongoing discussion between the two federal agencies over the ownership of the building.
EFCC spokesperson, Wilson Uwujaren, while condemning the action in a statement on Tuesday in Abuja, said it had wider implications for the fight against economic and financial crimes.
Uwujaren said that the EFCC was shocked by the action of the agents of DSS who barricaded the entrance into its Ikoyi's office with armoured personnel carriers.
"This development is strange to the commission given that we have cohabited with the DSS in that facility for 20 years without incident.
"By denying operatives access to their offices, the commission's operations at its largest hub with over 500 personnel, hundreds of exhibits, and many suspects in detention have been disrupted.
"Cases scheduled for court hearing today have been aborted, while many suspects who had been invited for questioning are left unattended.
"Even more alarming is that suspects in detention are left without care with grave implications for their rights as inmates," he said.
Uwujaren said that the action was in conflict with the efforts being made to tackle economic and financial crimes.
"The siege is inconsistent with the synergy expected of agencies working for the same government and nation, especially when there are ongoing discussions on the matter," he said.
Meanwhile, Dr Peter Afunaya, the spokesman of the DSS, has denied any rift with the EFCC.
Afunaya in a statement on the issue, said there was no rivalry between the service and the EFCC over and about anything.
He enjoined the media not to create any imaginary rivalry, adding that the two organisations were partners working for the good of the nation.
"It is not correct that the DSS barricaded EFCC from entering its office. No. It is not true.
"The Service is only occupying its own facility where it is carrying out its official and statutory responsibility.
"By the way, there is no controversy over No 15A Awolowo Road as being insinuated by the report.
"Did the EFCC tell you it is contesting the ownership of the building? I will be surprised if it is contesting the ownership," he said.
According to him, Awolowo Road was NSO headquarters and the DSS started from there.