Amnesty International (search) is asking the Defense Department whether the military used Taser electric stun guns on prisoners in Iraq or Afghanistan, saying it is uneasy about reports of mistreatment and abuse.

The human rights group said it made the request under the Freedom of Information Act after interviewing dozens of prisoners formerly held by U.S. forces.

"We do have credible evidence that certainly raises the question that Tasers might have been used," Gerald Le Melee, Amnesty International USA's deputy executive director, said Monday.

Amnesty has long expressed misgivings about the safety of Tasers and whether they are open to abuse because they can inflict severe pain without leaving marks. The group has urged law enforcement agencies to suspend the use of all electroshock weapons pending the outcome of a vigorous independent inquiry into whether the weapons pose health risks.

Taser International (search) contends its products reduce injuries and save lives by giving police an alternative to lethal force.

Amnesty's request concerning prisoners seeks information on computer chips stored inside Taser guns that record the date, time and duration of each electric shock administered.

The group also is requesting information about deaths that might have occurred after a Taser was used, as well as training materials and guidelines for how soldiers are to use the weapons.

Pentagon officials did not immediately return a call seeking comment.