The probe into six league and two cup matches comes after the Bulgaria Football Union (BFU) was handed information by European football's governing body UEFA which has now been passed to the prosecutor.
"I don't think we need to keep these matches in secret any more," Ognyan Stoichkov told local media. "I would like to thank the chief prosecutor for giving me the documents with all the details."
The matches under suspicion took place between Dec. 12 and May 16 with Lokomotiv Mezdra, who were relegated from the top flight last season, featuring in four games.
Champions Litex Lovech, runners-up CSKA Sofia and city rivals Levski Sofia were also involved in matches under suspicion.
The BFU has called for a full investigation. "We have to fight such things," said vice-president Atanas Furnadzhiev.
Media reports of widespread match-fixing and corruption have been rife in Bulgaria for years but no one has so far been convicted or brought to trial.
In 2007, UEFA investigated Bulgarian team Cherno More's 4-0 win over Macedonia's Makedonija in the Intertoto Cup.
Cherno More denied any wrongdoing.
The first documented manipulated game in the Balkan country took place in 1949 when Levski and city neighbours Akademik drew 1-1 to "help" CSKA to be relegated to the second division.
‘He instantly popped into our ratings as one of the best U21 midfielders in Europe. The impressive thing is Slot has made him into more of a no.6' Inside Ryan Gravenberch's transformation at Liverpool
‘I don’t think Liverpool would look at Ollie Watkins, a striker isn’t a pressing issue for them – it’s Arsenal who need one’ Former Reds star explains why his old club don’t need an out-and-out forward this summer
