The chase covered 7,000km (4,350 miles) and lasted three weeks

The jury was unable to reach a unanimous verdict as required under Australian law.

The men were arrested in August last year after Australian coastguards spotted their Uruguayan boat in the Southern Ocean.

A dramatic three-week chase ensued covering almost 7,000km (4,350 miles).

The fishermen were alleged to have caught almost 97 tonnes of the valuable and endangered toothfish when they were finally apprehended.

The men all pleaded not guilty to charges of using a foreign vessel for commercial fishing in Australian waters.

But prosecutor Hilton Dembo said: "This was no pleasure trip. This vessel was in icy cold conditions and these people were not out there catching fish for their Sunday barbecue."

Their nine-week trial ended with four days of deliberation but Judge Paul Healy dismissed the jury after they reported they were unable to reach the unanimous decision required.

The accused, who originate from Chile, Uruguay and Spain, have been granted bail while the authorities decide whether to order a retrial.