Gunther Klum - who had the German model with wife Ema - has spoken out about the breakdown of the couple's seven-year marriage.
He told US Weekly magazine: "We are very sad."
The couple - who raise seven-year-old Leni, Henry, six, Johan, five and two-year-old Lou together - were renowned for renewing their wedding vows every year, but released a statement claiming they have "grown apart".
They said: "While we have enjoyed seven very loving, loyal and happy years of marriage, after much soul-searching we have decided to separate. We have had the deepest respect for one another throughout our relationship and continue to love each other very much, but we have grown apart."
They added the protection of their children was their "top priority" in the wake of the split.
The statement read: "This is an amicable process and protecting the well-being of our children remains our top priority, especially during this time of transition.
"We thank our family, friends, and fans for their kind words of support. And for our children's sake, we appreciate you respecting our privacy."