Stolt Tankers has said it did not detain six Greenpeace activists who illegally boarded a tanker off Spain in a protest over palm oil.

The activists got on to the 39,000-dwt Stolt Tenacity (built 2017) in the early morning of Saturday while it was was sailing in international waters off the west coast of Spain.

"Immediately after the illegal boarding, crew of Stolt Tenacity provided the activists with a safety briefing, food and accommodation," it added.