Emphatically deny paying smugglers: Marles

Labor's immigration spokesman Richard Marles says the prime minister's refusal to deny the government is paying people smugglers leaves the door open.

Labor wants Prime Minister Tony Abbott to emphatically deny that Customs paid people smugglers to turn back asylum seeker boats.

Opposition immigration spokesman Richard Marles said Mr Abbott's refusal to deny the practice had left the door wide open to the idea the government was handing wads of taxpayer's cash to smugglers.

"Really it leaves one with the only possible assumption that that may well have been exactly what happened," he told reporters in Melbourne on Saturday.