The DSS had arrested Kanu last year at Lagos Airport, where he arrived from UK and had since been in detention and under trial over treasonable felony.
However, the FG had earlier asked the court to immediately dismiss and/or strike out the action for want of jurisdiction.
IPOB said that they instituted the case (which comes up October 5, 2016) in response to the Nigerian judiciary for not delivering their preferred judgment in the matter.
A statement from the Media and Publicity Secretary Mr. Emma Powerful on Tuesday alleged that the Federal Government had started making moves to influence the ECOWAS court.
“We are worried why the democratically elected government of President Buhari cannot obey court order in Nigeria and why his advisers cannot afford to let him know that the continued detention of Nnamdi Kanu and other IPOB members without trial will bring down the image of his government”, he said.
Meanwhile, ECOWAS court on Tuesday ordered the Federal Government to pay N15m as compensation to former National Security Adviser, NSA, Col Sambo Dasuki(rtd), over his “unlawful arrest”.