SYDNEY, Australia — Asylum seekers and refugees being held on Nauru under Australia’s harsh immigration laws are being deliberately subjected to suffering to deter others from trying to reach Australia, human rights researchers said after visiting the tiny island nation.

“The Australian government is commissioning the abuse of these people,” Anna Neistat, a senior director for research at Amnesty International who spent five days on Nauru in July, said by telephone from Paris on Wednesday. “It pays for the companies that detain the refugees, it pays for the guards, and it fails to provide adequate medical care. Australian taxpayers are funding it. And the world does not know this place exists.”

Michael Bochenek, senior counsel for Human Rights Watch, also visited Nauru, one of two offshore Pacific sites where Australia sends migrants who try to reach its shores by sea, and the groups issued a joint report on Tuesday about their findings. It is unusual for rights groups or news organizations to gain access to Nauru, whose government routinely denies them visas; Ms. Neistat and Mr. Bochenek did not identify their employers in their visa applications, according to the report.

Between them, the report said, the two spent 12 days interviewing 84 asylum seekers and refugees, including children, and spoke to service providers there. They said that asylum seekers were denied adequate medical care, that they were often the victims of crime and that depression and anxiety were rampant.