WARSAW, Poland — Polish military police say they have detained a former head of Poland’s military counterintelligence services for further questioning over alleged illegal cooperation with Russian security services in 2010.

Gen. Piotr Pytel denies the cooperation was illegal. The case relates to Poland’s and NATO’s agreement with Russia’s military intelligence that allowed for the passage of Polish troops back home from Afghanistan. Poland’s prime minister of the time, Donald Tusk, now European Union leader was questioned in the case last year.

On Wednesday, opposition politicians accused Defense Minister Antoni Macierewicz of ordering the detention in revenge against Pytel, who has criticized him.

The opposition has called for the dismissal of Macierewicz.