Murdered Melbourne woman Elly Warren will only get justice if the Australian Federal Police is given clearance to help with the African investigation, her mother believes.
Elly's family have ramped up calls for the Australian government to apply strong diplomatic pressure on Mozambique following a number of revelations around the 20-year-old's unsolved death.
The push for answers came after Elly's father Paul Warren travelled to the Mozambique beach town of Tofo, where she was found dead in November 2016.
In only a few days, he uncovered vital information that appears to have been missed or overlooked by local authorities.
Following renewed attention in the case, a Scottish woman told AAP how she escaped a sexual attack from a police officer in Tofo six years earlier, just 300 metres from where Elly's body was found.
Prime Minister Scott Morrison has raised Elly's death with Mozambique authorities "at the most senior levels".
Labor Leader Bill Shorten has been campaigning on behalf of Elly's family, writing to Foreign Minister Marise Payne, Department of Foreign Affairs and Trade secretary Frances Adamson and AFP commissioner Andrew Colvin.
"I am aware of apparent inconsistencies in the investigation into Elly's death conducted by the local authorities, including possible interference in the crime scene, and conflicting evidence," Mr Shorten wrote.
Elly's mother Nicole Cafarella wants the government to keep asking questions in a bid to allow the AFP to assist in the investigation.
Australian officials cannot go into another country to investigate the death of a citizen, but governments are able to invite foreign help in exceptional circumstances.
There is precedent for that happening, with AFP officers travelling to Croatia in 2010 for a 10-day mission to investigate the death of Melbourne woman Britt Lapthorne, whose body was found in Dubrovnik two years earlier.
"After two years we felt like we've exhausted all avenues," Ms Cafarella told AAP.
"We've realised they're (Mozambique police) heavily involved and we feel they're even responsible for Elly's murder and not willing to let the truth come out.
"This is not only to get justice for Elly, but to try and protect other tourists going there as well."
Ms Cafarella said the family had cooperated patiently with authorities for two years, but felt nothing would ever be achieved by sitting back and waiting.
"Even if Elly's murder was solved, we're still dealing with the loss of our daughter, so that's never going to change," she said.
"There's reminders of her every day, but knowing there's somebody responsible for her murder out there and they're not facing any consequences is even harder to take."
A Change.Org petition in support of Elly's family and their push for answers is closing in on 50,000 signatures.
