Up to 9,000 passengers at an airport in Medan may have been tested with the reused swab sticks, say police.
State-owned company Kimia Farma is now reportedly facing a potential lawsuit launched on behalf of the travellers.
Covid nasal swab testing has become routine in many countries hit by the global pandemic.
Police said they believed the scam had been happening since last December at Kualanamu airport in Medan, North Sumatra.
