10. ESMA shall refer matters for criminal prosecution to the national authorities concerned where, in carrying out its tasks under this Regulation, it finds that there are serious indications of the possible existence of facts liable to constitute criminal offences. ESMA shall refrain from imposing fines or periodic penalty payments where a prior acquittal or conviction arising from an identical fact or facts which are substantially the same has already acquired the force of res judicata as the result of criminal proceedings under national law.