Extradition and European Arrest Warrant Act
Chapter three - EXTRADITION PROCEDURE
Title I - Extradition at the request of another state
Article 21
(3) A refusal to extradite a foreign national against whom charges have been pressed or who has been convicted in another state shall not be an obstacle to prosecution within the Republic of Bulgaria where grounds exist to this effect.
Ne bis in idem
Ne bis in idem - ICC
EDIT.