South African authorities have discovered ZAR 720m ($51m) of cocaine on a boxship in Port Elizabeth.

The ANA news agency cited the directorate of priority crime (Hawks) as saying it had seized 70kg of the drug in 1kg bags last week.

The haul was believed to have come from Brazil.

The ship was not named, but had been the subject of an operation lasting 12 days and also involving Interpol.

Hawks chief Godfrey Lebeya said the cocaine was concealed on the bottom deck of the ship, under more than 3,369 containers.

The vessel was due to call in Singapore and India.

The owner and crew were not involved, but 60 boxes were confiscated.