Police stopped a public forum on the controversial agreement between the autonomous Bougainville Government and a Canadian company, Invincible Resources, from going ahead today.
The Bougainville Inter Church Women's Forum had called the meeting amid widespread anger at the deal with Invincible, which critics say gives the foreign company control of the province's extensive mineral resources.
The NGO's Monica Taga says as they were setting up for the meeting today, police advised them that they could not go ahead without a permit.
She says the need for such a permit surprised her.
"Normally, like when we organise forum, we don't seek approval from the police, from the law and order sector. We just go ahead and do so as a neutral organisation we thought that was okay."
She says the provincial government had earlier requested the forum be put off for two weeks to allow Ministers to attend, but her NGO had turned them down.
It's now scheduled for next Thursday.