Human Rights Watch is calling on the US and European and Arab countries not to transfer suspected Islamic militants to Egypt because they might face torture.
Egypt has waged a long campaign against Islamist militants
The New York-based organisation says a number of suspects sent by the US for questioning have been tortured.
It says the practice has increased since the suicide attacks in New York and Washington in September 2001.
The US says it only sends suspects to countries where the governments have said they will not be tortured.
"Egypt's terrible record of torturing prisoners means that no country should forcibly send a suspect there," said Joe Stork, the HRW deputy Middle East director in a statement.
The report is called Black Hole: The Fate of Islamists Rendered to Egypt. In it, about 60 people of Egyptian origin are identified as having been sent home from various countries.
The probable number was much higher, the report alleges, and scores of them are thought to have been tortured or faced serious mistreatment.
"Sending suspects to a country where they are likely to be tortured is strictly prohibited under international law," Mr Stork said.
There has been no immediate comment from the US or Egyptian governments about the report.