A protest at the former Marsden Point oil refinery is being monitored by the police.

It is not clear how many people might be there.

The refinery officially closed on 31 March, and the site became an import-only business.

A video posted on the 'Dig In at Marsden' social media page says the protest will be an "occupation" aimed at securing Marsden Point's refining capabilities.

Protesters have been claiming on social media they want to save "fuel security."

The video also references the anti-vaccine occupation at Parliament.

Channel Infrastructure, formally known as Refining NZ, said it is working with police to ensure any activity around the site does not disrupt operations or affect staff safety.