CONFIRMATION that Mr Williams was suffering from measles at the time of his death came from Public Health Wales.
Bosses also issued a warning that further deaths in relation to the measles outbreak were expected.
In a statement, Dr Marion Lyons, Director of Health Protection said: "The tests confirm only that the deceased had measles at the time of his death. Further investigations are being undertaken by the Swansea Coroner to establish the cause of death.
"My sympathies are with the family at such a tragic time. Whatever the cause of death in this case, we should not be surprised if, as the outbreak grows, we start to see deaths in Wales.
"Measles is a potentially fatal disease and around one in every 1,000 people who contracts measles in developed countries will die.
"We continue to work to end the current outbreak of measles, which is centred on the Swansea area, and which has now passed 800 cases.
"Those not fully vaccinated with two doses of MMR are highly likely to catch measles, which is highly contagious. We know that there are unprotected people in all age groups but we have particular concerns about the 10 to 18 age group. We are therefore urging all parents of children who have missed doses of MMR to arrange vaccination for them as a matter of urgency."
She said the MMR vaccine was recommended by the World Health Organisation, UK Department of Health and Public Health Wales as the most effective and safe way to protect children against measles. "The alarming numbers of cases of measles and continuing spread of the disease in Wales illustrates how vital it is for parents to get their children vaccinated," she added.