Li, who was formerly deputy director of the Standing Committee of Liaoning Provincial People's Congress, has been placed under "coercive measures," and further investigation is underway, the SPP said in a statement.
Coercive measures may include summons by force, bail, residential surveillance, detention and arrest.
Li has been expelled from the Communist Party of China (CPC) and dismissed from public office, the CPC's discipline agency announced earlier this month.
