Dawson, according to the Daily Mail, wrote, "The show was filmed in Padstow, Cornwall, in England, and the likeness to your mum is uncanny
"It has given us a strong sense of hope that at last her whereabouts may be known."
Lyn's sister Patricia denied Dawson's claims that she had appeared on the BBC programme.
"There is no way this is Lyn. Just the clothes tell me it's not her," she told the publication.
"She would never wear anything frilly or lacy. I have compared the jaw line and nose.
"Lyn came from a loving family and her disappearance left her adored daughters, who were two and four at the time, to grow up never knowing their mother or their mother's love."
Dawson was arrested on the Gold Coast on Dec. 5. almost 37 years after his wife went missing from their family home on Sydney's northern beaches in 1982.
Watch below: Police release official statement on Chris Dawson arrest