An employee made false allegations after receiving his dues from labour court

An employee, after receiving his dues from the labor court, is again making false allegations that he didn't sign a contract for salary reduction and has now approached the police and filed a criminal case against the Employer.

During the labor court investigation, the documents were sent to a crime lab for checking forgery, but the employee didn't go to the investigation officer and he was fined by the labor court for malicious allegations.

The labor case is closed and the employee labor card is canceled by the labor ministry. He now went and made a false complaint at the police station on the same topic that he didn't sign contract papers.

Please advise, as an honest employer, How can I protect myself from these false allegations by the staff?