Malaysian authorities have an unofficial agreement with the UN refugee agency not to place card holders in immigration detention centres, a deputy minister has revealed.

Deputy Home Minister Nur Jazlan Mohamed said this in disputing a report that refugees and asylum seekers were dying in immigration depots.

"Enforcement officers i.e police and the immigration department have unofficially respected UNHCR's request not to arrest their card holders and put them in detention centres so there cannot be refugees recognised by them in our detention centres...