The eight people detained for questioning on Tuesday were employees of the Nana Backpackers hostel where all the victims were staying, local media reported.
The owners of the hostel, which is now closed, previously denied serving illegal alcohol.
Speaking at Melbourne Airport, Mr Jones called on the Lao government to “continue to investigate” the case, adding that the families involved would try to “raise awareness of methanol poisoning”.
The other four victims were named as Simone White, a 28-year-old lawyer from the UK; James Louis Hutson, a 57-year-old American; and Danish nationals Anne-Sophie Orkild Koiman, 20, and Freya Wennerwald Sørensen, 21.
Mr Hutson was found dead in his hostel bedroom on November 13 with several empty glasses next to him. That same morning, Ms. Orkild Koiman and Ms. Venerwald Sørensen were also found unconscious in their rooms and rushed to a local hospital.
It is not yet clear how many more people may have been sickened by the suspected poisoning, and the deaths are still under investigation.
Last week, the manager of the hostel was among the few questioned by the police. He previously told The Associated Press that Ms Jones and Ms Bowles were the only tourists staying at the site who became ill after enjoying free drinks there before turning in for the night.
Commonly found in industrial and household products such as paint thinners, methanol is a colorless chemical sometimes used in bootleg alcohol.
Consuming as little as 25ml – which is about half an injection – can be fatal, but it can take up to 24 hours before a victim begins to show signs of illness through symptoms such as vomiting and abdominal pain.
Methanol poisoning has long been a problem in Southeast Asia, especially in the poor countries along the Mekong River, and the wider region has the highest prevalence of incidents worldwide.
The recent spate of deaths has put the spotlight on Vang Vieng, a notorious party town, and prompted new warnings from governments around the world about alcohol consumption in Laos.
