The three ICC witnesses said they feared for their security if they were returned to the Democratic Republic of Congo (DRC), whose president Joseph Kabila they accused in their testimonies.
Floribert Ndjabu, Pierre Célestin Mbodina and Manda Charif were sent back to their country on Sunday, according to an AFP report which quoted their lawyer Goran Sluiter.
Their expulsion marks the end of a three-year judicial headache for the ICC and its host country the Netherlands.
After a long procedure involving both the ICC and the authorities of the Netherlands, the Dutch Council of State decided on June 27 that the three witnesses could be sent back to the DRC.
The Dutch judges deemed that the DRC had provided enough guarantees with regard to their security, and notably a guarantee that they would not be sentenced to death.
Several NGOs had nevertheless called on the Dutch government not to send them back to the DRC. The three men had been held in a Dutch prison since June 4, after being held in the ICC Detention Facility since March 2011.
"It is disappointing that the Dutch government has decided to risk being complicit in possible human rights violations,” Géraldine Mattioli-Zeltner of Human Rights Watch told AFP.