Gene Simmons has claimed a series of "bad decisions" led to Ace Frehley's death.

The KISS frontman suggested substance abuse and a reluctance to change his "lifestyle" contributed to his former bandmate's fatal fall down the stairs at his home studio in New Jersey last month at the age of 74.

Gene told the New York Post newspaper: "He refused [advice] from people that cared about him -- including yours truly -- to try to change his lifestyle. In and out of bad decisions.

"Falling down the stairs -- I'm not a doctor -- doesn't kill you. There may have been other issues, and it breaks my heart.

"The saddest thing -- you reap what you shall sow, unfortunately."

The Morris County Medical Examiner previously confirmed Ace - whose real name was Paul Frehley - died after he suffered blunt trauma injuries to his head due to a fall, but according to reports, a separate toxicology report will be issued at a later date.

Gene found attending Ace's funeral "heartbreaking", and is particularly distraught that he won't be with the rest of the group when they enter the Kennedy Center Honors on Sunday (07.12.25).

He said: "It breaks my heart. Peter Criss, our founding drummer, Paul [Stanley] and myself went to the funeral, open casket.

"It was just heartbreaking.

"Saddest of all perhaps is that Ace just couldn't stay alive long enough to sit there proudly at the Kennedy Center and listen to -- I can't even tell you who's going to come out … really impressive people, just to say how much KISS meant to them.

"What can you say -- sad."

Gene revealed last month there will be a seat left empty in honour of Ace at the Kennedy Center Honors ceremony.

Speaking on stage in California, the 76-year-old rocker said: " I wanna take a moment just to tell you that somebody I've known for many decades who started the band with us, a guy named Ace Frehley…

"Very sad. Paul and myself and Peter Criss, we went to Ace's funeral. He sadly passed. And the saddest part of all, besides the pain and suffering to his friends, family, his daughter, his wife, his whole family, is that Ace didn't live long enough to be with us on December 7 when the president and everybody's gonna get up there and honour KISS in entering the Kennedy Center Honors.

"And the first person who's gonna walk out there and talk about how KISS changed his life is [country star] Garth Brooks, who's gonna host a little bit. Then he's gonna play Shout It Out Loud and knock it out of the park.

"And in Ace's memory, we're gonna make sure one of the four chairs is empty with Ace's name, because he deserves to be there in spirit, even if he can't be there physically."