The United Nations refugee agency said a boatload of 46 Vietnamese asylum seekers had their refugee applications rejected at sea before the Australian navy secretly returned them to Vietnam, according to an Australian Broadcasting Corp. report on Tuesday, according to AP. The UNHCR had asked the Australian government for details of the procedures used to assess their applications, UNHCR spokeswoman Vivian Tan said. "We're concerned that people may not have had access to proper procedures," Tan told ABC. "We are concerned that the group wasn't screened ... and assessed in a way that's fair and affective, that somehow their lives may be at risk," she said. The Australian navy routinely turns back boats carrying asylum seekers from Africa, the Middle East and South Asia. However, these boats are usually returned to Indonesia, where most of the sea voyages begin. Immigration Minister Peter Dutton has refused to confirm that the Vietnamese asylum seekers had been turned back, citing a policy of secrecy surrounding the interception of people-smuggling boats attempting to reach Australian shores. Local media reported that the boat left Vietnam in March and was intercepted by Australian customs and navy vessels early in April. The Vietnamese were offloaded from the HMAS Choules at the port city of Vung Tau last Friday week, the media reports said. Tan and Dutton did not immediately respond to requests for comments on Tuesday. In a rare update on its ocean surveillance of such boats, Dutton revealed in January that 15 asylum boats containing 429 asylum seekers had been turned back since his government was elected in September 2013.