Twelve Greenpeace campaigners who invaded and held up a cargo ship said to be carrying genetically-modified food were arrested last night by police who winched down onto the vessel from a helicopter.
The dozen had began their protest on the Panamanian-registered MV Etoile, one of the world's largest freighters, moments before it was due to dock at Rhoose, south Wales, on Sunday evening.
Greenpeace claims the vessel is carrying GM crops which are produced by US agriculture firm Archer Daniels Midland and intended for use in feed for dairy cattle in Britain.
It is believed the vessel had set sail from Louisiana, loaded with crops from Archer Daniels Midland. Early last evening, a helicopter dropped eight officers from South Wales Police onto the ship, which was anchored away from its intended destination of Royal Portbury Dock.
Police said 12 people are being held in custody for causing a public nuisance and will be questioned today. They confirmed that all the Greenpeace protesters have now been removed from the ship.
Acting Chief Constable Brian Greaves said the protest ended safely following negotiations between the owners of the ship and the protesters.
"We anticipate the vessel will meet the morning high tide and dock at Royal Portbury Dock tomorrow morning," he said.
By preventing a pilot from boarding the vessel, the protesters had ensured that the ship missed the last three high tides, the only time that a vessel of its size can safely enter harbour.
Police last night successfully detached two campaigners who had suspended themselves on ropes above the propeller to stop the boat moving. Three protesters agreed to descend the mast following negotiations.
But Greenpeace spokesman Ben Stewart claimed success in the protest last night.
"Tonight we thwarted a third opportunity to bring the boat into the dock," he said. "This was a result of the actions of two brave campaigners who suspended themselves above the propeller so the ship could not move.
"We hope people are now more aware that supermarkets like Sainsbury's, which claim to be GM free, are supporting huge imports of GM crops by selling milk from cows fed on GM products."