Creditor action against a forestry company has left some employees out of work - but not unemployed.

Hundreds of Northland workers lost their jobs in March, when creditors seized the property of some of the Kiwi Forestry International group of companies.

First Union says up to 25 Auckland workers haven't been let go or given redundancy, but have been told to stop coming to work.

General secretary Robert Reid says if the companies are insolvent, regulators shouldn't be letting them operate.

"These organisations should be keeping a watchful eye in regulating how business operates."

Despite this, Reid says regulators haven't started monitoring the companies.

"If these companies are insolvent, then they should not be trading while insolvent, and that is actually against the law."