Exclusive: legal experts say breaches could carry jail terms of up to 20 years, but no prosecution could be undertaken without consent of attorney general

Any Australian officials paying people smugglers to take asylum seekers back to Indonesia may have broken Australian laws carrying potential jail terms of up to 20 years and contravened international law, judicial experts say.



But any domestic investigation of legal breaches would have to be authorised by the government, which is stonewalling all discussion of the explosive claims, refusing to confirm or deny allegations that $30,000 was paid to six people smugglers to return asylum seekers to Indonesia in May.



Phillip Boulten SC, a leading Sydney barrister, and Nicholas Cowdery, a former director of public prosecutions in New South Wales, told Guardian Australia that an Australian paying people smugglers would likely be in breach of the provisions of the Criminal Code outlawing people smuggling, or assisting people-smuggling. But both pointed to the fact that the government itself would have to initiate and investigate any charges.

Facebook Twitter Pinterest George Brandis: legality of people-smuggler payments ‘academic’ – video

“On the face of it someone who pays thousands of dollars to an Indonesian mariner to take refugees back to Indonesia so as to breach Indonesian laws of entry may be breaching the Criminal Code,” Boulten said – including section 73(1), which makes people smuggling an offence, 73(3) dealing with aggravated people smuggling or 73.3A (supporting the offence of people smuggling).

But no such prosecution could be undertaken without the consent of the attorney general, George Brandis, Boulten said, and it could be possible for any person who paid smugglers to use as a defence the fact that they were acting to uphold a separate Australian law.

Cowdery agreed the payments appeared to breach the Criminal Code, but also pointed out the question of who would gather the evidence, given the Australian federal police work with customs on the vessels intercepting people smugglers.



The Australian Greens have written to the AFP asking them to investigate if any payments have been made to crews of boats carrying asylum seekers and if so what laws have been violated.



Bishop tells Indonesia to fix its borders over people smugglers payments claim Read more

“Paying cash bribes to boat crews amounts to people trafficking. The government does not have a mandate to break the law or a blank cheque to allow handing over wads of cash in the middle of the ocean,” Greens senator Sarah Hanson Young said.



The Coalition is under intense pressure to confirm or deny the claims that on 31 May six people smugglers were paid US$5,000 each to turn a boat containing 65 asylum seekers back to Indonesia, but consistently refuses to speak about “on water” or “operational” matters.



“I can be asked all sorts of questions in all sorts of ways, but the only question that matters is: is this government prepared to do what’s necessary to keep the boats stopped? The answer is yes,” the prime minister, Tony Abbott, has said when pressed to answer the claims, made by asylum seekers on board the boat to both Indonesian and UN officials.

During question time on Monday ministers repeatedly refused to comment on the issue on the grounds that they did not talk about “intelligence, security and operational matters.”

Abbott added a further grounds for his refusal to comment – that “this government does not feel the need to broadcast our intentions and tactics to our enemies … does not feel the need to big note ourselves to our enemies.”



Last week foreign minister Julie Bishop and immigration minister Peter Dutton refused to repeat their earlier firm denials that any payments had been made.



Asked why she had previously commented on operational matters, Bishop repeated that “this matter is now going to intelligence, operational and security matters, and in accordance with longstanding practice on both sides of the house I will not comment on it.”



In the Senate, attorney general George Brandis responded with a slightly different form of words, saying the government had “taken the necessary measures to succeed [in stopping the boats] where you have failed, and has at all times complied with the law.”

Abbott said Labor had enriched people smugglers by “half a billion dollars” with its failure to stop the boats.

The Labor party has asked the auditor general to investigate whether public money was used appropriately in the payments.

Federal law requires ministerial or cabinet oversight of expenditure, although a report in News Corp papers on Monday quoted a “senior source” as saying the payments had been made by an Australian Secret Intelligence Agency officer, in which case any such payments may have been approved by the Asis director general.



Tony Abbott sticks to 'stop the boats' in face of claims people smugglers paid Read more

The Greens will also try to force the government to produce documents in the Senate – a move routinely ignored by governments.



International law expert Prof Don Rothwell has said paying people smugglers is also likely to contravene international law, particularly the 2000 protocol to prevent people smuggling.



“This is what we cite to back interceptions at sea,” Rothwell told Guardian Australia. A complaint could only be lodged by Indonesia.



Madeline Gleeson, of the Kaldor Centre for Refugee Law, said: “If a state were to give money to smugglers and instruct them where to take people, it is possible that the state itself could be engaged in, or an accomplice to, a people smuggling operation. Whether or not such a payment would amount to a criminal offence would depend on the particular facts of the case.

“At the very least, though, it would be inconsistent with the general duty to prevent and combat people smuggling, which Australia has committed itself to as a state party to the UN Convention against Transnational Organized Crime and Protocol against the Smuggling of Migrants by Land, Sea and Air.”



Over the weekend, the Indonesian foreign minister, Retno Marsudi, ordered an explanation from the Australian ambassador, Paul Grigson, about the allegations and Jakarta launched its own investigation into the facts.



On Monday, Bishop hit back, telling the Australian newspaper: “I look forward to hearing the full ­results of Indonesia’s investigation of the people-smuggling crimes committed in Indonesia, including any breaches of passport and visa laws, and establishing whether the captains and crews of these boats are part of people-smuggling syndicates or are paid by them.



“The best way for Indonesia to resolve any concerns it has about Operation Sovereign Borders is for Indonesia to enforce sovereignty over its borders.”



Former Labor foreign minister Bob Carr told Guardian Australia Bishop’s rebuke would “inflame tensions” and jeopardise cooperation between Australia and Indonesia.