Nauru's former finance minister Roland Kun has been stopped from leaving the island with his passport confiscated.
The MP, who was suspended from Parliament in May last year, was due to leave on a Nauru Airlines yesterday but the flight was stopped as officials bundled Mr Kun off the plane.
Mr Kun said his passport is valid until October next year.
He made a request for a passport renewal earlier this week and Mr Kun said he believed the secretary of justice was behind both actions.
Mr Kun believed the action had been taken out of childish spite and to cause problems for him and his young family.
Mr Kun, who normally lives in Wellington in New Zealand with his family, said he arrived back on the island on Sunday, but had not been involved in the protests.
A protest was staged outside the Nauru parliament on Tuesday , with people demanding that five suspended MPs be re-instated, amid growing anger at a lack of scrutiny on government activity.
In recent weeks, the government passed a number of laws that have been criticised for limiting freedom of speech and the right to protest.
Mr Kun said the Nauru government had already denied his family access to Nauru by refusing his Australian-born wife a visa.
"I have a young family. I have an 18 month old child. They know that I am the full time caregiver in the period that we are being held in exile and they are now denying me access to my family by not allowing me out of the island. And I can only imagine that their motivation is to put my family in difficulty," he said.
A colleague and former justice minister Mathew Batsiua, who took part in the protest, was arrested on Tuesday and remains in custody until a decision on his bail is made today.
Attempts to get comment from the Nauru government have so far been unsuccessful.