Troy Austin, who has not spoken to the One Direction star for five years, says he now wants to heal the rift with his own dad who he has not seen for thirty years after recently undergoing an op to remove a cancerous tumour on his liver.
Troy, 49, has said he wants to track down his dad Harry Austin - and is also hopeful of a reunion with Louis at some stage in the future.
He said: “My life is changing now. I’m starting another chapter and I’d love for that to involve my dad.
“As for Louis, if he ever wanted to make contact then I would be happy for that to happen."
Troy, who lives in Doncaster, last saw and spoke to his dad in 1988 when he was a teenager.
He said: "He came to see me but I had arranged to go out and so I didn't hang around and spend time with him.
"Maybe that hurt him that I didn't want to spend time with him and he hasn't bothered since."
Troy, whose mother Tina died from bone marrow cancer at the age of 67, believes his dad, an ex-Royal Marine could be living in the south of England.
His mum and dad married in 1968 but due to Harry's military career, separated shortly afterwards and he remarried in 1972 in Portsmouth - to a woman whose surname he only knows as Privett.
Following his army career, Mr Austin worked as a station manager at St Mary's Fire Station in Southampton - but that's where the South Coast trail runs cold.
He is also understood to have worked in Saudi Arabia at one stage.
He added: "I've not had any letters or phone calls or anything. I'd love to see him and my daughter would love to see her grandad too.
"He will be 69 now and I'm reaching out to him to get in touch."
Troy split up with Louis's mum Johannah Deakin when the future pop star tot was just one week old.
She died in December 2016 at the age of 43 from leukaemia.
Now Troy has also undergone treatment for cancer after having the tumour removed in a four and a half hour operation at Sheffield's Northern General Hospital last week.
It followed years of heavy drinking and smoking but he insists he is now a changed man.
He said: “Each day I was smoking up to 25 cigarettes and drinking six to eight cans of Tyskie, a Polish lager. And my diet was terrible. It was Chinese and Indian takeaways and a lot of chips.
“Some days I wouldn’t eat at all but would just drink and smoke. I would drink to celebrate the good times and drink to cope with the bad. Whatever life threw at me I would drink.
He is also hopeful his search for his own dad will put him back in touch with Louis and he said: "I'd just like to say hello and get on like I would like to with my own dad."