Greenpeace on Monday sent a protest ship to meet a Russian tanker carrying the first oil drilled offshore in the environmentally fragile Arctic.

The ship, Rainbow Warrior, is captained by Peter Willcox, who was among campaigners detained by Russian authorities last year after staging a high-profile protest against Arctic drilling.

The vessel set sail from Rotterdam on Monday afternoon, Greenpeace said, and will seek to escort to harbour the Russian tanker Mikhail Ulyanov, which is delivering oil purchased by French energy giant Total.

The oil was drilled at the Prirazlomnaya platform, an offshore rig owned by Russian energy giant Gazprom and the site of Greenpeace's protest last September.

The protest, which saw two campaigners attempt to scale the rig, prompted Russian authorities to seize Greenpeace's Dutch-flagged Arctic Sunrise boat and detain the 30 activists and journalists on board.

Greenpeace argues that the Gazprom rig is an environmental catastrophe waiting to happen that risks ruining the pristine Arctic ecology of the southern Barents Sea where the deposit is located.

The activists had faced lengthy prison terms before Moscow announced amnesties.

"We want to escort the ship into the harbour," at Rotterdam, Greenpeace activist Patric Salize told AFP by telephone from aboard the ship.

He declined to say what kind of protest action the group might have planned.

There are 23 people on board the vessel, which may meet the Russian tanker on Tuesday night, another campaigner Willem Wiskerke told AFP, also from aboard the Rainbow Warrior.

"We do not disclose in advance what we are going to do, but I can assure you we will send a clear message to the world that this oil is very dangerous," Wiskerke said.

Greenpeace has accused France's Total of hypocrisy for buying the Arctic oil, after its CEO Christophe de Margerie said in 2012 that his company would not drill in the fragile region.

A Total spokesman in Paris confirmed the controversial purchase but insisted the company would not itself be drilling in the Arctic.

"The environmental risks are too high," the spokesman said, asking not to be named.

Greenpeace oil campaigner Ben Ayliffe accused Total of "real hypocrisy".

"Its CEO has already pledged not to drill in the icy waters of the far north, and yet he is apparently happy to buy the stuff if Gazprom takes on the risk," Ayliffe said in a statement.

"Mr. De Margerie cannot have his cake and eat it."

Greenpeace is suing Russia before the European Court of Human Rights for what it says was the illegal detention of its activists as it breached the right to freedom of expression.

Russian authorities are still holding the Arctic Sunrise icebreaker.