A legal case to see if Ashley Bloomfield acted lawfully locking the country down is being seen as critical.

Former parliamentary counsel and law drafter Andrew Borrowdale is taking him to the High Court.

He alleges the Director-General of Health used power he didn't have, to put the country into lockdown.

Otago University's Andrew Geddis told Mike Hosking it's critical to know if he acted according to the Health Act.

He says if these notices were unlawful, a whole lot of people have been arrested under them, who shouldn't have been.

“If the court agrees, it means the notices shouldn't have been given in that way, and Parliament should've legislated instead.

He says people who've been arrested and charged for breaching the lockdown can challenge that and any convictions.

Geddis says businesses can't sue the Government if they've gone out of business because of the restrictions.

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