A civil suit has been filed in a Jakarta court against PTTEP Australasia, and its parent company, Thailand's state-owned PTT PTTEP.
Indonesia alleges that the spill caused environmental damage in the archipelago's waters during the 10 weeks that the Montara oil field was producing oil and gas following a blow-out in a development well, caused by poor concreting, as the company attempted to speed up delivery of the drilling program.
The resulting explosion destroyed the West Atlas jack-up rig and severely damaged the Montara well head platform, although no workers were killed.
Indonesia's deputy minister for maritime affairs, Arif Havas Oegroseno, said the state was seeking damages from oil that crossed the maritime border with Australia, allegedly damaging coral reefs, seagrass meadows, seaweed fields and mangroves offshore East Nusa Tenggara, Indonesia's southernmost province.
It is seeking a ruling that would freeze the firm's assets in Indonesia and overseas if it does not pay up.
Oegroseno said Indonesia had tried to negotiate with PTTEP to come to a resolution but was not satisfied with their response, with PTTEP denying the oil slick ever reached Indonesian waters.
He said PTTEP had failed to front an independent commission which included the former Indonesian and Thai foreign ministers in 2012 leaving negotiations at a standstill, so legal action was the best course of action.
"We feel that they are not serious in handling this issue," he said.
The government originally planned to launch the suit in April.
PTTEP has previously said comprehensive studies clearly showed "no lasting impact on the highly sensitive and biodiverse ecosystems in the areas closest to Indonesian waters".
In August last year about 13,000 Indonesian seaweed farmers launched a $A200 million class action against PTTEP Australasia in Sydney, claiming the accident devastated their livelihoods.
The seaweed farmers are being represented by a lawyer from the law firm Maurice Blackburn, who says the spill destroyed seaweed farms, harmed marine life and impacted on the health of residents in the province.
A PTTEP Australia spokesperson told Energy News in March it would continue to engage with Indonesia "in good faith".
PTTEP says it has always accepted responsibility for the Montara incident, and commissioned the largest independent scientific research program ever undertaken into the Timor Sea environment to discover there had been no lasting impact on the region.
It said satellite imagery, aerial survey images and trajectory modelling concluded that 98% of the oil remained in Australian waters and that no oil reached the Australian or Indonesian coastlines.
PTTEP maintains that it was "improbable that the seas and coastline of Nusa Tenggara Timor would have been impacted" given the reefs closest to Montara, where the oil and dispersant concentrations were at their greatest, did not show lasting impacts.
PTTEP was fined $510,000 for the spill in 2012, and it was convicted for three occupational health and safety offences and one other offence for failing to verify barriers in the well.
The Montara project is some 250 kilometres north-west of the Kimberley coast of Western Australia.
PTTEP will soon add additional production wells to the project.