The court in St Petersburg granted bail to Ekaterina Zaspa, a 37-year-old doctor from Moscow, pending further developments in the case.
Earlier on Monday the same court ruled that Australian Colin Russell would continue to be detained until at least 24 February pending the ongoing investigation into the protest.
Two other activists, a freelance photographer and a freelance videographer were also due before the same court on Monday regarding applications to extend their detention by Russia’s Investigative Committee.
Twenty-eight environmental activists and two freelancers have been held in Russia since 18 September after an attempt to scale the Gazprom Neft Shelf-operated Prirazlomnaya drilling platform to raise a banner highlighting Greenpeace’s opposition to Arctic exploration.
If convicted of hooliganism, they could face up to seven years in jail.
While prosecutors are not pursuing in court their original more serious charges of piracy, they have yet to issue a formal written statement withdrawing the charges, Greenpeace said.