A Northland couple was so terrified after being "harassed and illegally detained" by a "masked aggressor" at a community COVID-19 roadblock that they were forced to call the police for help.

Rata and her husband were driving to do their weekly supermarket shop in Kaikohe when they were stopped at a Tai Tokerau Border Control checkpoint, and then "detained" when they didn't hand over their home address.

The roadblocks, set up by former Maori Party MP Hone Harawira, have been in place since last month.

They were established with the intention of stopping international tourists travelling around the country during the coronavirus crisis, but their main function now is to prevent Kiwis breaking their household 'bubbles' during the alert level 4 lockdown.