The Government Communications Security Bureau (GCSB) has declined Spark's proposal to use Huawei 5G equipment in their network.
A release from the GCSB says the decision was made after "a significant network security risk was identified" with the Chinese owned telco.
A statement from Spark on the matter says that their proposal "involved the deployment of Huawei 5G equipment in Spark’s planned 5G Radio Access Network (RAN), which involves the technology associated with cell tower infrastructure."
The company says the decision will not affect plans to launch Spark's 5G network by 1 July 2020.
The US has warned the Huawei is a security threat due to the possibility of Chinese government interference. However, Huawei has denied carrying out any intelligence work for the Chinese government.
Australia banned the company from its 5G network.