Disturbing new questions have been raised about the role of doctors and other medical professionals in helping the Central Intelligence Agency subject terrorism suspects to harsh treatment, abuse and torture.

The Red Cross previously documented, from interviews with “high-value” prisoners, that medical personnel helped facilitate abuses in the C.I.A.’s “enhanced interrogation program” during the Bush administration. Now Physicians for Human Rights has suggested that the medical professionals may also have violated national and international laws setting limits on what research can be performed on humans.

The physicians’ group, which is based in Cambridge, Mass., analyzed a wide range of previously released government documents and reports, many of them heavily censored. It found that the Bush administration used medical personnel — including doctors, psychologists and physician assistants — to help justify acts that had long been classified by law and treaty as illegal or unethical and to redefine them as safe, legal and effective when used on terrorism suspects.

The group’s report focused particularly on a few issues where medical personnel played an important role — determining how far a harsh interrogation could go, providing legal cover against prosecution and designing future interrogation procedures. The actual monitoring data are not publicly available, but the group was able to deduce from the guidelines governing the program what role the health professionals played, assuming they followed the rules.