BULGARIA - PENAL PROCEDURE CODE
Part one. GENERAL RULES
Chapter two. FUNDAMENTAL PRINCIPLES
Art. 17 (2) No person may be detained for more than 24 hours without the permission of the court. The prosecutor may direct detainment of the accused till he/she is brought before the court.
(3) The respective body shall immediately notify a person, named by the detained, about the detainment.
(4) If the detained is a foreign citizen, the Ministry of Foreign Affairs shall be informed immediately about the detainment.
(5) The court, the prosecutor and the investigating bodies must release every person who has been unlawfully deprived of freedom.
Fair trial standards
Rights during investigation - arbitrary arrest or detention and deprivation of liberty
EDIT.