The United Nations said it obtained video footage from a military hospital in Homs showing patients there were victims of torture.
The U.N. office said Syrian security forces are known to have used torture for "many years." Methods include beatings, electric shocks and psychological torture.
The video footage showed what the United Nations said were security forces dressed as doctors abusing patients.
"Security agents, in some cases joined by medical staff, chained seriously injured patients to their beds, electrocuted them, beat wounded parts of their body or denied them medical attention and water," a statement attributed to OHCHR spokesman Rupert Colville read. "Medical personnel who did not collaborate faced reprisals."
The video in question was obtained by London's Channel 4 News. It was allegedly taken by a Syrian employee at the hospital in Homs.
Navi Pillay, U.N. high commissioner for human rights, told the Human Rights Council in Geneva last week that Damascus should be referred to the International Criminal Court for its brutal crackdown on anti-government groups.
An official in the White House told The Cable, a blog published by news magazine Foreign Policy, that Washington was considering aggressive action to remove Syrian President Bashar Assad from power.
"These moves are going to invest the U.S. in a much deeper sense with the opposition," the administration official said on condition of anonymity. "U.S. policy is now aligned with enabling the opposition to overthrow the Assad regime. This codifies a significant change in our Syria policy."