The widow of Robert Brown, a former engineer, has called on his former colleagues to come forwards with information about his employer.
Mr Brown died in 2012 of lung cancer and it was believed potential exposure to asbestos as a teenager caused him to develop the disease.
While asbestos has many short-term risks, it can often lie dormant for decades before scarring the lining of the lungs and causing Mesothelioma; a form of cancer that has no cure and is nearly always terminal.
When Mr Brown was diagnosed he was given six months to live, but passed away nine weeks later after the cancer spread to his liver and brain, causing extensive damage.
Speaking to the London Evening Standard, Mr Brown's wife Ann, who was the man's husband for 20 years before his death at the age of 65, asked for anyone employed at Brightside Heating and Engineering in Westminster between 1962 and 1968 to come forward.
A post-mortem examination of Mr Brown's body showed that there were numerous pleural plaques in his lungs, which his family believes were caused by exposure to asbestos when he worked at the heating company at the age of 15.
Speaking to the Evening Standard, Mrs Brown said, "I want justice for him and all the others who worked there.
"It's just awful. The kids and I are finding it really hard. He never saw his granddaughter, he's missed out on so much. It has affected us all."
Mrs Brown is now working with lawyers to arrange an industrial disease claim.
Part of this will involve finding out who is legally responsible for Brightside Heating and Engineering, which no longer exists.
At first it was thought that Carillion Singapore acquired the firm, but a spokesperson from the company denied this and said its assets are now owned by another business, meaning it is not responsible for the case.
The name of the other company was not revealed by the representative.