Green MP Jan Logie has been released by Sri Lankan immigration officials, after being detained for three hours.
This comes in the lead up to the Commonwealth Heads of Government meeting in the Sri Lankan capital, Colombo, which starts on Friday.
Prime Minister John Key will attend, despite calls for New Zealand to take a stand against allegations of human rights abuses.
Ms Logie, and an Australian Green Party senator, Lee Rhiannon, went to Sir Lanka to hear firsthand from local people about allegations of human rights abuses.
Human rights advocates want an independent investigation into allegations government forces committed war crimes towards the end of a 26-year civil war that ended in 2009.
The United Nations says 40,000 civilians were killed in the last five months of the conflict.
Speaking from the hotel lobby where she was being held, Ms Logie says immigration officials turned up, as she and Ms Rhiannon were about to start a media conference.
She says the officials shut the conference down, took their passports and detained them at their hotel.
Ms Logie says they've both been released and told to leave the country.
On Sunday evening, Ms Logie had to wait several hours before she could leave Sri Lanka, on her scheduled flight.