An excited George Dryden said he's found a company that can do DNA tests on hairs that belonged to Diefenbaker, even though they no longer have the roots.
In addition, the museum in Saskatchewan that has the hair has also found a DNA report done on a tooth believed to have belonged to the former prime minister.
"We've got two irons in the fire," Dryden said. "This will prove it definitely, once and for all."
According to Dryden's lawyer, the museum has opted to keep confidential the name of the person who requested testing of the tooth "some time ago." Apparently the tooth was destroyed but the DNA report has now turned up.
Both the hairs and DNA report are expected to be sent to a Toronto-based testing company early next week.
"We should have an answer, hopefully, by next week," he said.
Last month, Dryden, 43, said he was giving up on further attempts to prove his paternity after a private investigator retrieved a used Q-tip from a distant Diefenbaker relative identified by a genealogist he had hired.
Genetic testing of the swab revealed a link between Dryden and the relative — enough to show he was a Diefenbaker by blood, even if it didn't conclusively prove the parent-son link.
"For me it's good enough, but apparently for everybody else, it's not good enough," Dryden said Wednesday.
"That's why I wanted to take this final step and get this hair tested."
When the centre initially said it had found Diefenbaker's hair, Dryden was scornful, saying they were useless for genetic testing without the roots. The company he has now hired believes that's not the case.
"Apparently, they don't need the root," he said.
The businessman, who bears a strong resemblance to the former Conservative leader, claims his mother, Mary Lou Dryden, had an affair with Diefenbaker in the 1960s. Diefenbaker, always believed to have been childless, died in 1979.
She was a known confidante of the prime minister and there were longtime family whispers about the father of her child.
Dryden only found out last year that the man he had long believed was his dad was in fact not his biological father.