Francois-Henri Pinault has spoken publicly for the first time about the son he fathered with supermodel Linda Evangelista.
The French businessman - married to actress Salma Hayek - is currently involved in a child support dispute with Linda, who is seeking $46,000 a month.
He has refuted her lawyer's claims that he has been paying "zero" towards raising four-year-old Augustin.
Speaking to the French edition of Elle magazine, Francois-Henri said his son is an important member of his family.
He said he has "recognised" Augustin since 2007 and that "at every possible opportunity he has participated in my family life, whether in France or the United States."
"He is totally integrated within my family," he said, adding that Valentina, his three-year-old daughter with wife Salma, treats him like a brother.
Augustin was born in October 2006 – more than eight months after Francois-Henri separated from Linda, and around the time he started dating Salma.
They were married in 2009.
It was only in July of this year that Francois-Henri was revealed to be Augustin's father.
In numerous interviews, Linda had described the man who fathered her son as a "New York architect".
But this summer the truth emerged when she filed court papers seeking support from the French billionaire.
"In the filing, it says the child was 'born out of wedlock' to (petitioner) Linda Evangelista, 46, and that (Pinault) acknowledged (her) allegation," a source familiar to the filing told People at the time.
"It says, 'It is decided that Pinault is the father is (Evangelista's son) Augustin James."
Lawyers acting for Linda have requested that she receive $46,000 a month from Francois-Henri, because, as a single mother, she needs financial support to pay for around-the-clock nannies and chauffeurs.
At a hearing last month, Mr Pinault's legal team questioned her need for a team of former police detective drivers at a cost of $175,000 a year, and $80,000 a year for a 24-hour nanny.
Asked by the judge about her working hours, Linda said: "On days when I do not work, I am working on my image.
"I have to hit the gym, I have beauty appointments. I have to work towards my next job and maintaining my image, just like an athlete.
"When I work it can be a 16-hour day."
Francois-Henri is one of the richest men in France; his company PPR has shares in luxury brands including Gucci, Stella McCartney and Alexander McQueen.