"A regional police department outside capital Sofia informed us that they initiated an investigation over possible match-fixing and it's the first time they're doing something like this in Bulgaria," BFU's press officer Pavel Kolev told Reuters.
"Finally, something can happen... It's about this season's match between teams of the bottom half of the table."
Media reports of match-fixing and corruption have been rife in the Balkan country for years.
The BFU have forwarded claims of match-fixing to the prosecutors on several occasions but no one has been brought to trial and the European Commission has criticised the authorities for doing little to fight the problem.
"I can tell you that we also got information about this match from UEFA over the early-warning system," Kolev said.
Last July, the BFU threatened to expel Pirin Gotse Delchev from the country's top division over "their failure to respect the principles of fair play".
The BFU's statement came after Pirin were widely criticised for their performance in a 7-1 defeat at then league leaders Botev Plovdiv and local media reported that players from the Gotse Delchev-based side have been involved in match-fixing.
Bulgaria passed amendments to its penal code in 2011 that makes match-fixing and illegal sports betting a crime - anyone convicted of attempting to fix events will face up to six years in jail.
The first documented manipulated game in Bulgaria took place in 1949 when Levski and city neighbours Akademik drew 1-1 to "help" bitter rivals CSKA to be relegated to the second division.