Cardiff Blues No 8 Nick Williams – a former New Zealand Super Rugby back rower – is the cousin of Sonny Bill Williams and the brother of former Chiefs outside back Tim Nanai-Williams.
“We are close as a family and I regularly speak to Sonny Bill,” Nick Williams told The Guardian.
However, he could not shed any light on his All Black relative’s post-World Cup plans.
“Whatever he does, I am sure he will be good at it. He is someone who keeps his professional and private lives separate.”
Meanwhile, Nick Williams may extend his own 15-year professional career.
The 35-year-old, a Junior All Black in 2006, made his debut for North Harbour and the Blues in 2004, but has been in Europe for a decade since joining Munster in 2008.
“The heart still wants to go on but it depends on how well the body holds up,”the 130kg forward said.
“I am in negotiations about carrying on, but with my wife first. I never thought I would still be involved when I reached 30 given the way I play, so going on this long must have something to do with my genes.”
Unlike many Kiwi rugby compatriots, Williams has no plans to head home after his final pay cheque.
“Whatever I do after the World Cup, I will not be returning to New Zealand. My wife and I will be settling in Cardiff with our three girls, all of whom were born in Europe.
“I have worked here for 12 years and it has become a home away from New Zealand; Wales could do with another Williams!”