Australia's military held 46 Vietnamese asylum seekers at sea for nearly a month and rejected their refugee claims following brief interviews, Australian officials said Tuesday.
Maj. Gen. Andrew Bottrell, who oversees Australia's border security operations, told lawmakers that an Australian vessel intercepted the asylum seekers on March 20.
Following interviews that lasted as little as 40 minutes, the men, women, and children were determined to not qualify for refugee protection under U.N. conventions, Bottrell said.
He said the asylum seekers were then sent back to Vietnam on the Australian navy ship, after Vietnamese officials gave assurances they would not be punished upon arrival.
Bottrell said Australia has turned back at least 18 boats of asylum seekers since September 2013, when Australian Prime Minister Tony Abbott came to power.
Abbott's conservative government has come under fire by rights groups for turning back the boats. He says the policy is the most effective way to deter people smugglers.
Hundreds of asylum seekers have died in recent years while en route to Australia on rickety, overcrowded boats.
Under Australia's policy, all asylum-seekers arriving by boat are sent to offshore camps in Papua New Guinea and the island of Nauru for detention and processing.
Most of the voyages originate in Indonesia and are filled with asylum seekers from South Asian or Middle East nations that have been hit by unrest.
Bottrell said the anti-people smuggling operation has been successful, but "people smugglers continue to try to take advantage of vulnerable people by convincing them to get on boats to Australia."