Updated

A report by environmental group Greenpeace says Thai fishing fleets are operating thousands of kilometers (miles) from home in unregulated waters to dodge government oversight over illegal fishing and onboard human rights abuses.

The report released Thursday highlighted the case of two boats that returned home after more than a year at sea with six Thai and Cambodian fishermen on board dead from beriberi, a disease caused by Vitamin B deficiency better known for striking sailors more than a century ago.

Both had parked themselves off the coast of Madagascar, where they stayed for months. They transferred their catch to "reefers," refrigerated cargo ships, to avoid government regulators while still getting their fish to market.