The Chinese Embassy has accused New Zealand of lodging groundless accusations about cyber attacks in a malicious smear against China.

The Embassy says New Zealand has adopted a "cold war mentality" by joining an unprecedented alliance of United States allies in denouncing China for state-sponsored hacking.

The joint statement against China was released last night, with the Minister responsible for the GCSB, Andrew Little, saying the agency had linked Beijing sponsored actors known as the Advanced Persistent Threat 40 to malicious cyber activity here.

Mr Little has declined an interview, saying there was nothing to add to last night's statement.

The Prime Minister, Jacinda Ardern, also declined an interview, while Foreign Affairs Minister, Nanaia Mahuta, was unavailable to speak with us.

Māni Dunlop spoke to Waikato University law professor, Alexander Gillespie.