Jacinda Ardern on social media, local media reported on Friday.
A Twitter post containing a photo of a gun and caption “You are next’’ was sent to the prime minister.
The post had been up for over 48 hours before the sender’s Twitter account was suspended after it was reported by various people.
According to the report, the suspended account contained anti-Islamic contents and white supremacist hate speeches.
Terror attacks hit New zealand’s Christchurch recently, killing no fewer than 50 people and injuring 50 others.
In the aftermath of the terror attacks, Prime Minister Jacinda Ardern vowed to change the gun law in the country.