Judge Luis Roberto Barroso on Tuesday approved the extension requested by Brazil's federal police, Tercera news outlet reported.
In early February, then-Director General of the federal police, Fernando Segovia said that no proof had been found that Temer's decree favored logistics company Rodrimar SA. Segovia was dismissed earlier in the day by the newly created Public Security Ministry.
Temer's May decree extended the existing contracts for port concessions. The investigation was launched based on a wiretap that allegedly suggested a former presidential aide was discussing a possibility of an exchange of concessions favors for bribes.
Brazil has been mired in a corruption scandal involving its state oil firm Petrobras, which has been found to have paid bribes to officials to secure lucrative contracts. In October, the Brazilian parliament voted against a graft probe into President Temer who was accused by the chief prosecutor of having run a criminal ring with links to Petrobras.