Three Cardiff hospitals have been named in a list of 25 UK hospitals which have bought potentially contaminated body parts allegedly stolen in the USA.
The hospitals have acted to reassure patients
They are the University Hospital of Wales, Llandough Hospital and the privately-run Bupa Hospital.
The UK Medicines and Healthcare Regulatory Authority (MHRA) has concluded that the possibility of infection is low.
The authority says it is up to hospitals whether they inform patients.
Dr JJ DeGorter, director of clinical services for Bupa hospitals, said no patient's health had been put at risk.
"As soon as Bupa Cardiff hospital was contacted regarding the MHRA tissue graft recall, we identified three patients who had already been treated," he said.
"On the basis of medical advice, we are confident that there is no risk to their or any other patient's health."
Dr DeGorter added: "We have been reassured by the supplier that the appropriate action has been taken to ensure that this doesn't happen again."
Cardiff and Vale NHS Trust runs the two other Cardiff hospitals named.
A trust spokesperson said: "A small number of our patients have received bone allografts using tissue from Biomedical Tissue Services.
"Our doctors are in the process of contacting the patients involved directly to reassure them and offer medical advice and support.
"However, we would ask them not to worry unduly about this incident as it does not significantly increase the risks normally associated with this type of procedure.
"All other patients are completely unaffected by this incident."
The Welsh Assembly Government said in a statement: "In any such incident where there is any doubt expressed by the Standard's Inspectorate about the quality of tissue, the normal hazard warning and advice will have gone to the trusts for them to implement."
As well as the three hospitals in Wales, 22 in England are also named as having bought potentially contaminated body parts allegedly stolen in the US.
In one case a bone from New York was used in a hip replacement operation at the Royal National Orthopaedic Hospital, in Stanmore, Middlesex.
It has also emerged in a BBC Radio Five Live investigation that some patients have not been told about concerns surrounding implanted bones.
Police in New York are investigating claims that the managers of a company called Biomedical Tissue Services took body parts without the consent of next of kin.
Over 80 body parts were involved in the UK which could have been used on dozens of patients.
The UK Medicines and Healthcare Regulatory Authority has concluded that the possibility of infection from the bones is low.
The hospitals were named following a freedom of information request submitted by the BBC.