Australians are showing little interest in studying Indonesian language, despite a downgraded travel warning that has opened up student travel to Indonesia.

Professor Tim Lindsey, an expert in Indonesian law at the University of Melbourne, said there were now fewer Australian students studying Indonesian at Year 12 level than 40 years ago.

"Indonesian studies in Australia were quite strong in the 1970s, but since then for a range of reasons it's declined quite significantly," he said.

"There seems to be a strange ironic link between the fact that during the period when Indonesia opened up and democratised after Suharto fell, the number of students in Australia interested in studying Indonesian has declined.

"There were, in fact, more students taking Indonesian at Year 12 level across Australia in the early 1970s than they are now.

"And that's in absolute numbers and despite the fact that the population was 30 per cent smaller then, so not only have we not kept track, we've actually fallen below that level."

Professor Lindsey said it was hoped the re-wording of a travel warning to Indonesia in 2012 may have encouraged more students to study Indonesian language.

He said a 10-year warning urging Australians to reconsider travel to Indonesia discouraged many schools from sending their students to the country.

"Now, if students can't get an immersion opportunity to study a foreign language, that will limit their capacity," he said.

"And it's a reasonable decision that without immersion their capacity to learn a foreign language will weaken, and so this fed into a really big falling off in schools, Indonesian language teaching and that naturally flowed on into our universities."

However, figures from the NSW Board of Studies show the change has had little effect.

In 2012, there were 119 students enrolled in Higher School Certificate Indonesian language, compared to 125 in 2013 and 121 in 2014.

Indonesian tertiary study in danger

Professor Lindsey said if the current rate of decline continued, Indonesian language would not be an option at Australian universities in a decade.

"We've seen the numbers of schools teaching Indonesian fall quite dramatically over the last 15 years and that's followed through in many of our universities," he said.

Professor Tim Lindsey is director of the Centre of Indonesian Law at the University of Melbourne. ( Supplied: University of Melbourne )

"A significant number of universities have now dropped the teaching of Indonesian language, and we're reaching a position where Germany may have more universities teaching Indonesian than Australia.

"Australia is the only western tradition country in Asia, yet it rates the lowest among all OECD countries by a long shot for second language skills.

"If current trends continue it may end up teaching very little Asian languages except to kids of an Asian background or context."

Professor Lindsey said while the recommencement of high school student travel to Indonesia was welcomed, more action was needed.

"It seems like some sort of major policy failure that we should be located in Asia and looking at the collapse of Asia literate capacity outside people of an Asian origin," he said.

"We do, rightly or wrongly, face a situation of declining Asia literacy both in terms of languages and Asian studies.

"If that is seen as something necessary then in the end we are going to need to have governments investing funding in subsidising Asian languages and Asian studies in schools."

Regional high school maintains links

Indonesian language teacher Linda Keyte said her students from Mullumbimby High School in northern New South Wales had managed to maintain links to Indonesia through the Federal Government's BRIDGE (Building Relationships through Intercultural Dialogue and Growing Engagement) program.

The program has seen several groups of Indonesian students travel to Mullumbimby to be hosted by local students' families.

Many Mullumbimby students have also travelled to Indonesia on unofficial trips during school holidays to stay with the Indonesians they had hosted.

"I joined thinking it would be a good boost for the teaching and learning of Indonesian at our school, and to have a real connection with real people and make the conversation and learning more relevant for students," Ms Keyte said.

She said Mullumbimby High was the first public school to resume student trips to Indonesia in 2014.

Indonesian students watch Aboriginal dancers at Mullumbimby High School. ( ABC North Coast: Samantha Turnbull )

"Indonesia is Australia's closest neighbour and I think we were very Indonesian literate 20 or 30 years ago," Ms Keyte said.

"As the numbers of Australian students learning languages across the board has plummeted, it's become very difficult to maintain programs like this in schools because of the travel ban."

Another group of Mullumbimby High School students will travel back to Indonesia on an official school trip later this year.

Mullumbimby High School's Aboriginal education officer Scott Sentance said Indigenous students particularly enjoyed the opportunity to host Indonesian visitors.

"Amongst tribal groups, it's always a blessing to share culture with one another," he said.

Mr Sentance and the school's Indigenous students performed dances for and gave art lessons to the Indonesians.