Prime Minister John Key says he has not been approached by police investigating claims of illegal spying by the Government Communications Security Bureau.

Key said if approached by police he would be more than happy to speak with them.

This comes after police appointed a "senior" team to investigate the claims of illegal spying.

Green Party co-leader Russel Norman said he had received a letter from Detective Superintendent Southern Peter Read.

Norman had complained about allegations GCSB intercepted communications by millionaire Kim Dotcom because they mistakenly believed he was not a New Zealand resident.

"I am very pleased that senior police investigators have started inquiries and expect to make an initial report by November 15," he said.

A QC was appointed to provide oversight to the inquiry.

"It is reassuring to know that police intend to interview key witnesses to get to the bottom of how a New Zealand resident was illegally spied upon," Norman said.

He hoped Prime Minister John Key and Deputy Prime Minister Bill English would be questioned.

"Spies must be held to the same standards as other New Zealanders. They are subject to the laws of this land and must be held accountable by the police and the courts when they violate those laws."

- © Fairfax NZ News