Nicky Hager's lawyer is calling on New Zealand's spy agencies to implement more thorough safety checks after it was yesterday announced the New Zealand Security Intelligence Service illegally spied on the journalist.

Your playlist will load after this ad

Yesterday, it was announced that the acting Inspector General of Intelligence and Security upheld a complaint by Mr Hager against the spy agency for acting unlawfully in attempting to uncover his journalistic sources.

The Security Intelligence Service (NZSIS) accessed two months of phone records from Mr Hager's home phone, and three months of records from a New Zealand Defence Force (NZDF) officer's mobile and home phone line. It came after Mr Hager's 2011 book Other People's Wars, about New Zealand's involvement in the war in Afghanistan.

The NZSIS has been directed to apologise and have given an assurance it won't happen again.

Your playlist will load after this ad

But in talking about the case, Mr Hager's lawyer Felix Geiringer told TVNZ 1's Breakfast today the effort to undermine a journalist's investigation by revealing their source was "a significant threat to our democracy".

"It's really important that journalists are able to receive information like this when it's appropriate and what we can't do is have our investigative bodies using their extraordinary powers to protect themselves from embarrassment."

As well as the SIS, the Government Communications Security Bureau (GCSB) has also been in trouble for it's unlawful spying on Kim Dotcom. At the time in 2013, SIS boss Rebecca Kitteridge said, "it is vital that an organisation that exercises intrusive powers of the state does so in a way that is entirely lawful".

And while Mr Geiringer said the Inspector General had shown itself to be a powerful office for protecting New Zealanders, these cases were examples of it's limitations.

"Even before the Inspector General was alerted to it we had Miss Kitteridge writing to Mr Hager, in this case, telling him that she couldn't confirm or deny whether such activities had taken place because to do so would jeoparadise national security. Now, the Inspector General has found that there was no national security issue in play," he said.

"So here we still have Rebecca Kitteridge covering up unlawful acts by her own organisations used to protect their own reputation and not protect national security at all."

Your playlist will load after this ad

But Mr Geiringer said it was important for the spy agencies to have its important powers so they can "get the bad guys".

"What we need to learn from these experiences, in my view, is that whenever you want to give an agency, any agency, extraordinary powers, you also have to put extraordinary efforts into implementing the safety checks.