The new video, posted on social media sites like Facebook this week, shows a man in fatigues sexually assaulting and beating at least four blindfolded men whose hands are bound to window and door frames.
The man, who is seen grinning, is aided by another man wearing shalwar-kameez.
The blindfolded men's screams and the laughing of someone off-camera are audible in the video, media reports said today (June 15).
Though the authenticity of the video could not immediately be ascertained, it has emerged at a time when the Pakistani armed forces are facing intense scrutiny for several incidents of extra-judicial killings and abuses.
Paramilitary troops and policemen were filmed gunning down five unarmed foreigners, including a pregnant woman, in the southwestern city of Quetta last month after declaring them "suicide bombers".
It was later established that none of the foreigners had weapons or explosives.
Last week, a TV cameraman filmed a paramilitary Pakistan Rangers personnel shooting Sarfraz Shah, 18, at point blank range in a park in Karachi. The youth was left to bleed to death, the video repeatedly aired on news channels showed.