More families could be affected by the removal, apparently without consent, of body parts from nuclear plant workers.
The case of 65 former workers at Sellafield sparked initial concerns
An inquiry has been launched into the removal of human tissue from workers at Sellafield in Cumbria for medical tests since the 1960s.
The inquiry, led by Michael Redfern QC, could take up to a year.
It has now been widened to include Atomic Weapons Establishment in Berkshire and UK Atomic Energy Agency (UKAEA) at Harwell in Oxfordshire.
The inquiry will ask why samples were taken and if next of kin were informed.
On Tuesday, Mr Redfern said he was looking into cases between 1962 and 1992 and appealed for families who believed they may have been affected to come forward.
In a statement Mr Redfern said: "We have started investigating all the cases referred to us. It is likely there will be more.
"We will be investigating whether the removal, retention, testing and disposal of organs was conducted in compliance with the legal requirements in force at that time.
"Our purpose is to encourage research and organ donation but strictly in compliance with the law."
Mr Redfern also led the investigation into the removal of children's organs at Alder Hey Hospital in Liverpool.
He added: "It is not the intention to restrict or undermine research. The very essence of disease identification and cure depends upon it."
The inquiry has been welcomed by the Human Tissue Authority (HTA) which was set up in 2005 to regulate the removal, storage, use and disposal of human bodies, organs and tissue.
Adrian McNeil, chief executive of the HTA, said: "This investigation reaffirms the importance of establishing a clear regulatory framework for obtaining consent."