The Fu Tian docked in a lagoon near West Pomio, where 200 landowners gathered to protest the logging activities of Malaysian owned company Rimbunan Hijau (RH) and its subsidiary, Gilford Limited.
Greenpeace activists on board theit vessel the Esperanza painted "Stop the Land Grab" on the side of the Fu Tian early on Monday morning, Greenpeace forest campaigner Paul Winn said.
"The Fu Tian should be departing for China soon and we're trying to slow that down," he told AAP. "We still claim that this is unlawful logging."
But Greenpeace spokeswoman Jessa Latona now says the blockade is over.
She said Greenpeace temporarily prevented logs from being loaded on a barge.
"We painted on the side 'stop the land grab' and while we were doing that the logging people on the ship threw rocks at us," she said.
"It didn't take long for us to get the picture pretty clearly that we could not continue with the blockade."
New Guinea Islands Police Commander Anton Billie said Greenpeace's protest was illegal because the group had failed to seek permission from provincial police.
Source: AAP / Sydney Morning Herald / Australia Network News, 26 October