Flag of convenience (FoC) shipping is a major security risk along Australia's coastline, the International Transport Workers Federation (ITF) has warned.
A Senate committee examining the practice recently made nine recommendations, including a comprehensive assessment of maritime security.
But the ITF is concerned that the Senate committee's interim report will be forgotten.
ITF national co-ordinator Dean Summers told PM he had high hopes for the Senate inquiry.
Listen to this interview with Summers here.
"Border protection put it very succinctly themselves — they've said that reduced transparency or secrecy surrounding the complex financial and ownership arrangements are factors that make FoC ships more attractive for use in illegal activities, including by organised crime and terrorist groups," he said.
"Now, if that's not enough for our own government to sit up and take notice, then they're missing the point completely.
"And this is from (Australian) Border Force, people who know their game."
The inquiry was first launched in response to the suspicious deaths of three seafarers on board the Japanese-owned ship Sage Sagittarius.
The ship carried the flag of Panama and relied on a Filipino crew before becoming a floating crime scene in 2012 after the three crew members died during one six-month period.
The Senate committee's interim report, released in May, recommended a whole-of-government assessment of the potential security risks of FoC ships and foreign crews.
But the inquiry has now lapsed, due to the dissolution of the Senate and the House of Representatives.
"I understand it's part of the parliamentary processes," Mr Summers said.
"We accept that. We'll be looking very carefully after the election to ensure that the process continues, because the issues aren't finished.
"In fact, since the interim report came out, we've been inundated by more cases."
'There are crooked laws there'
One of the cases forwarded on to the ITC since the interim report was released involves the Panamanian-flagged ship Spring Hydrangea, which reported a man overboard just over a month ago.
The ship was in international waters, 148 kilometres from Dampier in Western Australia at the time. It was on its way to China.
The Panama Maritime Authority has confirmed that it was made aware of the incident and began to investigate on May 2.
But the deputy chief of the authority's Marine Accident Investigation Department said the ship was then sold, and its registry was transferred to Liberia in West Africa.
As a result the authority said it could no longer pursue the matter.
West Australian Labor senator Glenn Sterle, chair of the Senate inquiry, said the latest incident showed the issue must be taken seriously.
"There are crooked laws there, that are available for these ship owners to just allegedly sell and de-register and move or transfer to other jurisdictions like Liberia," Senator Sterle said.
"There was a man overboard, there's a human being who has gone missing, and their response is 'Sorry, nothing to do with us, it's been sold and flagged in Liberia'."
Ships slip under the radar
The Australian Maritime Safety Authority conducted a search for the Filipino crew member, but only his life jacket was found.
The now Liberian-flagged ship has since been renamed MV Monegasque Eclat and was last seen at a port in China.
The Australian Federal Police have said they are not involved in the matter.
Mr Summers said it showed how easy it is for ships to slip under the radar.
"The bottom line is that the flagged state — the country where the ships are registered — have a responsibility to investigate accidents, near misses and deaths," he said.
"In this case, they're saying 'Oh, sorry, it's been transferred to Liberia. There won't be any investigation'."
Future of Senate committee to be decided after election
A spokeswoman for the Federal Minister for Infrastructure and Transport, Darren Chester, said the Government took any concerns about foreign-flagged ships, and their compliance with Australian laws, seriously.
All foreign vessels are also assessed according to their risk profile, with the Australian Border Force collecting pre-arrival information to confirm the safety and security status of the ship and crew.
The spokeswoman pointed out that the Senate committee's interim report did not reflect the views of the committee as a whole.
Two senators, Bill Heffernan and John Williams, disagreed with the recommendations.
After the election, new members of the committee will decide whether to continue or finalise the inquiry.