The suspension came hours after Ukrainian journalists at Bihus.info published an investigation into Brahinsky and his family growing asset portfolio, suggesting the official was involved in corrupt schemes. Brahinsky has administered Kyiv Metro for a decade.
"Hard evening with unpleasant revelations," Klitschko said in a Telegram message.
"Viktor Brahinsky is hereby suspended from his duties as Kyiv Metro director. Perhaps, he will not contest this and will resign voluntarily."
Klitschko indicated that law enforcement should further investigate the claims brought to light by the journalists.
Klitschko added that the issue tarnishes the reputation of both his office and the citizens of Kyiv.
Bihus.info drew attention to high-value properties acquired by Brahinsky’s relatives, including his mother's purchase of luxury apartments and his estranged wife's construction of an upscale cottage in Kozyn, Kyiv Oblast. The investigation also detailed an alleged transaction where Brahinsky's sister bought land from him at a highly inflated price.