Should the courts rule that Unibet has breached the Polish Gambling Act, Kindred could face the maximum financial penalty of as much as PLN 28.9 million (€6 million).
Reports also suggest that other Polish gambling license holders are considering joint legal action against Kindred for its activity in the market.
A Warsaw District Court has since warned Kindred and Unibet that it cannot continue to offer betting or advertise its products in Poland while the case is ongoing.