David Haussmann and Jonathan Beauchamp were arrested with the so-called Arctic 30 in September after Russian authorities boarded their vessel, the Arctic Sunrise, in international waters.
The 28 Greenpeace activists, a freelance photographer and a freelance videographer, were protesting against drilling for oil in Arctic waters. They had focussed their attentions on a drilling platform owned by gas giant Gazprom. Two people tried to climb onto the platform and hang a banner.
Mr Haussmann was one of nine who were granted bail at a hearing earlier this week. So far 12 of the group have been granted bail.
Today, Greenpeace has retweeted a tweet that announced Mr Haussmann's release: "@gp-sunrise 5h "BREAKING: David Haussman (sic) from New Zealand is released on bail and walks out of SIZO 4 in St Petersburg #FreeTheArctic30".
It was not known when Mr Beauchamp's case will be heard.
The bailed environmentalists were told they would be released from jail if they could provide financial surety of 2 million rubles (NZ$73,224).
The group was initially charged with piracy, but that charge was downgraded to hooliganism last month. The new charge carries a maximum penalty of seven years jail.
