Up to 9000 passengers at an airport in Medan, Indonesia may have been tested with reused swab sticks.
Police believe the scam has been happening since last December in North Sumatra..
Passengers are required to have a negative test if they want to fly, and the airport offered tests onsite.
Following complaints from passengers had received false positive results police sent in an undercover office to pose as a passenger
Five employees have since been arrested.
The company said last week it had dismissed the workers allegedly involved and would fully support a police investigation.
“I strongly condemn the actions of unscrupulous Kimia Farma officers,” Indonesia’s state-owned enterprises Minister Erick Thohir said on Twitter.
“Such action must be subject to very strict punishment.”