Cowell formed the classical group in 2003
The Spanish baritone died on 19 December aged 53 after contracting the Delta variant of Covid-19.
He had been placed in an induced coma in a Manchester hospital earlier this month as the group were forced to cancel their UK Christmas tour.
According to the singer’s ex-wife, Geraldine Larossa, Cowell had rung the hospital and “offered to help with anything” before Marin died.
The Britain’s Got Talent judge formed Il Divo in 2003 for the label Syco Music, which is a subsidiary of Sony Music. The group later parted ways with Cowell.
In a video statement, Larossa told Hello Magazine: “Simon Cowell personally phoned the hospital and offered to help with anything.
“To help him, send him a plane in case they could fly [to Spain] sooner, but it was impossible. He was very sick and he would not have survived the pressure of the plane.”
Larossa went on to thank celebrities including Barbara Streisand for their condolences.
At the time of Marin’s death, Cowell paid tribute to the singer. He wrote on Twitter: “I am finding this so difficult to put into words how I feel right now. I am devastated Carlos Marin has passed away.
“He loved life. He loved performing and always had so much appreciation towards the fans who supported the group from day one. Rest in peace Carlos. I will miss you.”
Larossa and Marin married in 2006 before splitting in 2009. The pair, however, remained close until he died, according to Hello Magazine.
Following Marin’s death, the singer’s family have claimed that he could have been saved if he had been treated for Covid-19 in Spain instead of the UK.