The U.S. government is accused of withholding knowledge about chemical weapons inside Iraq.

In one of the bitterest ironies of the Iraq War, a New York Times investigation found American soldiers suffered injuries after being exposed to chemical weapons discovered in Iraq.

The chemical weapons are not ones the U.S. went to war over, but old, discarded weapons manufactured during the 1980s with help from western countries, including the U.S., who were aiding Iraq in its war against Iran, CBS News correspondent David Martin reports.

The Pentagon previously acknowledged that some caches of old chemical weapons were found, but the New York Times identified 17 soldiers who were exposed to the weapons.

The weapons consisted of the nerve agent sarin and the burning agent mustard gas

The soldiers were quoted by the Times saying they were told to keep their discovery secret. As a result, they were denied proper medical treatment and the Purple Heart which soldiers receive when wounded on the battlefield.

One former sergeant is quoted by the times as saying "I felt more like a guinea pig than a wounded soldier."

And to add insult to injury, some of the shells were found in areas of Iraq now controlled by the terrorist group the Islamic State of Iraq and Syria (ISIS).

It is not known whether they could still use those weapons in the current battle for Iraq.