A Human Rights Watch (HRW) report has detailed the damning state of immigration detention centres in Malaysia that house thousands of refugees and asylum seekers, listing claims of human rights violations and abuse.

The Malaysian government is detaining about 12,000 migrants and refugees, including 1,400 children, in conditions that put them at serious risk of physical abuse and psychological harm, HRW said in the report released today.

The 60-page report, "We Can't See the Sun: Malaysia's Arbitrary Detention of Migrants and Refugees", documents Malaysian authorities' punitive and abusive treatment of migrants and refugees in 20 immigration detention centres across the country.

Immigration detainees can spend months or years in overcrowded, unhygienic conditions, subject to harassment and violence by guards, without domestic or international monitoring.

"Malaysian authorities are treating migrants as criminals, arbitrarily holding them for prolonged periods in immigration centres with almost no access to the outside world," said Shayna Bauchner, Asia researcher at HRW. "Malaysia's degrading and abusive immigration detention system denies migrants and refugees rights to liberty, health, and due process."

Human Rights Watch interviewed more than 40 people, including former immigration detainees, family members, lawyers, humanitarian aid staff, and former immigration officials, the report said.

Malaysian law makes all irregular entry and stay in the country a criminal offence, with no distinction among refugees, asylum seekers, trafficking victims, and undocumented migrants. There is also no legal limit on the length of immigration detention, leaving migrants at risk of being detained indefinitely. Authorities have detained more than 45,000 irregular migrants since May 2020.

Former detainees described a bare and brutal existence inside the immigration detention centres, also called depots, with limited food and hygiene supplies, frequent water shortages, strict and unpredictable rules, and the ever-present threat of punishment.

"We would get beaten when we asked for more food, took an extra mug of water to shower, or asked for a blanket for the cold," said a Rohingya refugee previously detained at the Belantik immigration depot.

Detainees are required to present themselves for "muster calls", or roll calls, several times a day. Some last hours, with detainees ordered to stay silent, heads down and not moving, even to use the bathroom.

"If we made any noise, we would be punished, like hanging from the wall, pushups, squats, walking like ducks, or standing under the hot sun for hours," said an Indonesian woman held in the Tawau immigration depot.

Migrants are held without recourse to judicial review or mechanisms to appeal their detention. The Malaysian government's use of prolonged, judicially unsupervised immigration detention violates international human rights law prohibitions against arbitrary detention, HRW said.

Both ill-treatment and inadequate medical care have led to hundreds of deaths in immigration detention facilities in recent years, according to government data and witness testimony. One migrant worker said officers tortured him and 13 others for days after they tried to escape, beating them with bricks and batons and standing on their chests. Two of the detainees ultimately died.

Anti-migrant policies and practices, as well as xenophobic rhetoric have risen in Malaysia in recent years.

The Malaysian government has denied the United Nations refugee agency UNHCR access to immigration detention centres since August 2019, leaving the organisation unable to review asylum claims or protect detainees registered as refugees. Malaysia has also not ratified the Refugee Convention, the HRW report said.

Detained refugees and asylum seekers said immigration officials used threats, degrading treatment, and violence to block requests to meet with the UN refugee agency or to coerce them to return to their countries of origin.

When a UNHCR-registered ethnic Chin refugee and dozens of other refugees at the Ajil depot protested the lack of access to the UNHCR and threats of deportation, the guards assaulted them. "We were brought outside and beaten on our hands and feet five times with two rubber pipes that were taped together," he said. "The pipes were filled with metal wires. I fainted after the third hit."

Children detained in the immigration centres face the same abuses as adult detainees, including denial of medical care, inadequate food, and ill-treatment. Malnutrition is widespread, the report said.

The Malaysian government's immigration detention of children contravenes international law, it said.

Although the government has for years discussed alternatives to detention for children -- including in its pledges to the UN Human Rights Council -- there has been little progress.

The UN Working Group on Arbitrary Detention has called for immigration detention to be gradually abolished, stating that "migrants must not be qualified or treated as criminals", and that immigration detention should only be used "as an exceptional measure of last resort, for the shortest period and only if justified by a legitimate purpose, such as documenting entry and recording claims or initial verification of identity if in doubt."

The Malaysian government should reduce its reliance on immigration detention and move toward abolishing it entirely, Human Rights Watch said.

The authorities should immediately stop detaining refugees, children, trafficking victims, and other vulnerable migrants for immigration-related reasons.

The government should instead pursue community-based alternatives to detention that would not only counteract abusive and unnecessary immigration detention, but also make the immigration system more cost-effective, efficient, and humane.

"Malaysia should seriously consider adopting measures used by other countries that better manage immigration objectives," Bauchner said. "Instead of maintaining abusive detention centres, the government should develop alternatives that protect the rights of children, refugees, and other vulnerable migrants."