Val Kilmer was “bed-bound” for years and his death was not unexpected, his family has reportedly revealed.

Kilmer, who starred in films such as Top Gun, The Doors, and Batman Forever while earning a reputation as a Hollywood bad boy, died this week, age 65.

The cause of death was pneumonia, The New York Times reported on Tuesday (US time), citing his daughter Mercedes Kilmer.

It has emerged that Kilmer was “bed-bound” for several years as his health deteriorated and he was very frail during his final days, Sky News reports.

Kilmer was diagnosed with throat cancer in 2014 and underwent radiation and chemotherapy treatments, as well as a tracheostomy that permanently gave him a raspy speaking voice.

He wrote an ethereal final social media post on Instagram the month before his death.

In the final post on March 22, Kilmer posted a picture of a watercolour painting.

“It’s got that late-night glow. Cool tones with a low burn, like when the camp fire cools down but you’re still wide awake,” he wrote.

Val Kilmer’s final Instagram post.

The California-born, Juilliard-trained actor was one of Hollywood’s most prominent leading men in the 1990s before numerous spats with directors and co-stars and a series of flops dented his career.

Fellow actors, including Josh Brolin and Matthew Modine, paid tribute.

“See ya, pal. I’m going to miss you. You were a smart, challenging, brave, uber-creative firecracker. There’s not a lot left of those,” wrote Josh Brolin on Instagram.

Modine wrote on X: “RIP Val Kilmer. If it wasn’t for our chance encounter at the Source [Hollywood restaurant] in 1985, I may never have been cast in FULL METAL JACKET. Thanks, Val.”

Over the years, Kilmer gained a reputation as temperamental, intense, a perfectionist and sometimes egotistical.

“When certain people criticise me for being demanding, I think that’s a cover for something they didn’t do well. I think they’re trying to protect themselves,” Kilmer told the Orange County Register newspaper in 2003.

“I believe I’m challenging, not demanding, and I make no apologies for that.”

He made his film debut in the spy spoof Top Secret! (1984) before appearing in the goofy comedy Real Genius (1985).

He then rocketed to fame as Tom Cruise’s co-star in the smash 1986 hit Top Gun (1986), playing naval aviator Tom Iceman Kazansky.

Kilmer starred in director Ron Howard’s fantasy Willow (1988) and married his British co-star Joanne Whalley, with whom he had two children before divorcing.

One of his most challenging roles came in director Oliver Stone’s The Doors (1991) in which he played Jim Morrison, the charismatic and ultimately doomed lead singer of the influential rock band The Doors.

To persuade Stone to cast him, Kilmer put together an eight-minute video of himself singing and looking like Morrison at various points in his life. Kilmer’s own singing voice is used in the film.

The Doors ushered in the highest-profile years of his career.

In the 1993 Western Tombstone, he played Old West gunfighter Doc Holliday.

He had two commercial successes in 1995, co-starring with Al Pacino and Robert De Niro in the crime drama Heat and succeeding Michael Keaton as the Caped Crusader in Batman Forever, the third instalment in the Batman series.

The noisy, bloated and plodding Batman Forever was received tepidly by critics, and Kilmer was upstaged by co-stars Tommy Lee Jones and Jim Carrey.

Kilmer pulled out of the next Batman movie. Director Joel Schumacher called Kilmer “the most psychologically troubled human being I’ve ever worked with”.

Things only got worse for Kilmer when he clashed with co-star Marlon Brando during the notoriously troubled production of The Island of Dr Moreau, which flopped in 1996.

“There are two things I would never do again in my life,” John Frankenheimer, who directed the movie, said afterward.

“I will never climb Mt. Everest and I will never work with Val Kilmer again. There isn’t enough money in the world.”

Post-cancer, his films included a Top Gun sequel, The Snowman (2017) and Paydirt (2020), which also featured his daughter Mercedes.

The Chicago Tribune wrote in 1997 that Kilmer was a member in good standing of Hollywood’s bad boys club.

He was also nominated multiple times for worst actor in the annual Razzie awards honouring the worst in cinema.

Handsome with light brown hair, Kilmer’s personal life sometimes overshadowed his work.

His relationships with various high-profile actresses included singer Cher and model Cindy Crawford.

-with AAP