Labor volunteers have been caught on hidden cameras bragging about using Australian taxpayer funds to work on a US presidential campaign and interfering with Donald Trump and Hillary Clinton campaign signs.
In a video posted online by the conservative undercover campaign group Project Veritas Action, four Australians are recorded saying they received taxpayer funds for flights, accommodation and daily expenses while organising for Democratic senator Bernie Sanders' presidential campaign, a possible breach of US election law.
Former Australian National University Labor Club president Ben Kremer is identified in the video trying to remove campaign signs for Republican candidate Donald Trump in Manchester, New Hampshire, acknowledging in the secret recording that the tactics were not legal.
"F--- you, Donald," he says in the video.
Mr Kremer tells the video crew Sanders campaign officials had told him stealing rival campaign signs was not allowed and says he also switched Hillary Clinton campaign literature with Sanders materials. Other volunteers were not depicted tampering with signs.
"Bernie is about listening and saying "f--- you" to the establishment," he said on the video.
Australian Labor Party national secretary George Wright told Fairfax Media he had launched an investigation to confirm the federal government-funded Australian Political Parties Democracy Program complied with US election laws.
He said behaviour shown the video, reported by right-wing media outlet The Washington Times, was "completely inappropriate" and was also being investigated.
Mr Kremer, a party member and campus organiser in Canberra, tells the undercover film crew that volunteers were instructed not to post information about their work on social media, because it could cause the Coalition government to cancel the program.
Mr Kremer has been contacted for comment.
"They have had issues in the past, where like if I put a photo up of myself with the Statue of Liberty ... the next morning it would be on the front of a newspaper with ... 21-year-old student users taxpayer money to go on holiday. What a disgrace."
He says there is nothing "wrong" with the program, but some people would be unhappy volunteers were working on the Sanders campaign, "because not everyone is left-wing".
Senator Sanders is challenging Mrs Clinton for the Democratic nomination.
Two other Australian are also seen in the video talking tactics - including one discussing stealing signs from the Clinton campaign.
Western Australia Young Labor president Rebecca Doyle is identified in the video saying the ALP's international branch had coordinated travel, accommodation and funding to assist the Sanders campaign, including $60 daily stipends.
Ms Doyle has also been contacted for comment.
Sanders' campaign national press secretary Simone Sanders tells Project Veritas Action she is not sure about the Australians' involvement.
The group identifies itself as a journalism organisation and has previously targeted the Clinton campaign and other Democrats. It has faced lawsuits over other videos posted online.
Project Veritas Action is one of many partisan outfits who use online videos and investigations to influence presidential elections in the US.
Mr Wright said he believed the program, administered by the Department of Finance, was compliant with all US election laws. Labor, the Coalition and the Greens have each received funding from the controversial program.
"I have initiated an investigation to ensure that it is. We believe that our program is compliant but clearly the behaviour of these individuals in the video is, on the face of it, completely unacceptable and I will also be investigating that."
He said four Labor members had been involved in the exchange program, and they had all returned to Australia since its completion.
"They are there as observers and they should just be observing, not posting stuff on social media and certainly not doing the type of things they are depicted doing."
Mr Wright said Project Veritas Action's methods were questionable.