Advocates say maps that show the Montara oil spill was closer to Indonesia than first thought make a case for a proper study of the disaster's effects.
Maps that show oil from the Montara spill closer to Indonesia than official records state have spurred advocates to call for an independent study in neighbouring waters.
The Australian Maritime Safety Authority maps were released through Freedom of Information to the Australian Lawyers Alliance.
They show the oil sheen was just 69km from Indonesian shores - closer than the 94km figure quoted by the company responsible, PTTEP Australasia, and in the Montara Commission of Inquiry report.
Advocates say this strengthens the case for a thorough study of whether the catastrophe has damaged Indonesia.
For 74 days in 2009, millions of litres of oil gushed from the Montara well head into the Timor Sea, the pollution spreading towards Indonesia.
Fishermen who saw oil floating in their fishing grounds have since suffered massive financial losses, as well as health problems.
But they have no proof these are linked to the spill because there has been no independent scientific study in Indonesian waters.
AMSA says the maps were among the material given to the commission of inquiry.
"These maps are not secret," a statement read.
" ... while the figures quoted on these maps are accurate, these maps were produced as Power Point slides for briefing material and are not to scale."
The ALA says the new maps would suggest that oil pollution got within 37km of Indonesia, using the closest point, the southern coast of Rote.
But AMSA says the maps cannot be used to extrapolate accurate distances.
The ALA's Greg Phelps says the maps underscore the need to look closer at the effects of the spill on Indonesia.
Communities that were impoverished before the spill are now disadvantaged further and desperate for Australia's help to find answers.
"It's incumbent on the Australian government as well as the oil company to get together and make sure this independent study occurs," Mr Phelps said.
"With such a wealth of data here, it should all be analysed in the context of a proper study."
A spokesman for PTTEP said the company quoted 94km as the point where oil sheen was seen closest to Indonesia because it was the figure in the official 2010 report.
"This is consistent with PTTEP's statements to date and supported by independent studies published by the Australian Department for the Environment which found 98.6 per cent of Montara oil stayed in Australian waters, the majority within 23km radius of the well head," he said.
"Beyond this zone the weathered hydrocarbons were predominantly lighter waxy films and exposure was of short duration."
Lawyers will discuss the newly revealed maps and the campaign for independent research in Indonesian waters at the ALA national conference this weekend.