Mr Dotcom has previously been reviewed by both agencies. The SIS checked him in October 2010 when he applied for residency, notifying police at the time of the FBI's interest in his Megaupload file-sharing business.
The GCSB was then drawn into the FBI case after a request from the police's Organised and Financial Crime Agency of NZ, which was helping the FBI inquiry. Ofcanz staff sought the bureau's help in monitoring Mr Dotcom in the month leading up to the police raid in January, which saw him arrested on FBI charges of copyright violation. He faces an extradition hearing to the United States.
Mr Norman said the ability for the SIS to "veto" investigating officers undermined the equal position each person was meant to have under the law. "The problem is they are the sister organisation of the organisation being investigated."
Meanwhile, Mr Dotcom's new Mega service has suffered a setback. The Me.ga domain is registered in the West African nation of Gabon, which was reported yesterday as wanting to suspend the site.