Antonio D'Amico and Versace had been together for 15 years before the fashion designer was shot dead outside his Miami Beach home in 1997 by sociopath and serial killer Andrew Cunanan (Criss).
Ricky Martin is playing D'Amico in the sequel to the popular series "The People v O J Simpson".
The 58-year-old said the murder scene did not resemble the real scene when he discovered Versace's body, reported People magazine.
D'Amico revealed he was drinking coffee on the porch of their mansion when Versace's murder happened.
"I felt as if my blood had turned to ice. The house had stained glass windows so we couldn't see what had happened from inside, so we had to open the gate. I saw Gianni lying on the steps, with blood around him. At that point, everything went dark. I was pulled away, I didn't see any more," he said.