"Law & Order: Special Victims Unit" star . A friend of Belzer's confirmed to that the actor was suffering from health issues. The veteran actor was 78.

A notable comedian, Belzer eventually found the role of a lifetime when he became . He first appeared as Munch in NBC's "Homicide: Life on the Street," only to return as the character in "Law & Order: SVU." Belzer was committed to the "Law & Order" character for over 20 years, playing him across several shows, though "SVU" was the detective's main bread and butter.

"The writers got to know me," Belzer said in a 2017 chat with . "The character of Munch was really close to how I do things. It was a dream come true for me and an utter delight to play this character for so many years." 

With Belzer so attached to his "SVU" role, it's no surprise that several of the actor's former colleagues are reacting to his passing. "Good bye mon ami. I love you. #TheBelz," shared Belzer's "SVU" co-star Christopher Meloni on . Attached to Meloni's heartfelt message was a photo of the Elliot Stabler actor kissing Belzer on the cheek. Meloni followed up his original reaction by

a photo of Belzer and Mariska Hargitay on the set of the "Law & Order" series, reminding fans just how adorable the two were.

Mariska Hargitay and more pay tribute to the iconic SVU castmember

Mariska Hargitay, best known to fans as the unstoppable Olivia Benson in "Special Victims Unit," took to to pay tribute to her late costar. In an emotional post, Hargitay described Ricard Belzer as a "dear, dear friend." "I will miss you, your unique light, and your singular take on this strange world," Hargitay wrote.

"I feel blessed to have known you and adored you and worked with you, side by side, for so many years. How lucky the angels are to have you. I can hear them laughing already. I love you so very much, now and forever." 

District Attorney Casey Novak actor Diane Neal expressed her grief on , sharing several photos of Belzer and herself to her followers. "#UncleBelzer my hero, Neal wrote. "We always had fun. Genuinely. At work. On vacation. Anywhere. #RichardBelzer #Belzer #Belz The man who made every moment better. I will miss you terribly."

Ice-T, who plays Fin Tutuola on "SVU," was saddened to hear the news of Belzer's death.

Fin and Munch were longtime partners at Manhattan's SVU, and the duo had a back-and-forth that couldn't be matched. "Highs and Lows... After one of the most amazing weeks of my life. I wake up to the news I lost my friend today. Belz is gone.. Damn it! But remember this..'When you ARE having real fun and are Truly Happy. ENJOY it to the fullest! Cause Pain is inevitably coming.' I'll miss you Homie," Ice-T .

Law & Order writers and producers also remembered Richard Belzer

Oscar-winning actress Marlee Matlin, who made a brief appearance in "SVU" as Dr. Amy Solwey also shared her memories of Belzer on . "Richard Belzer was one of the most kindest and welcoming actors when I guested on two episodes of 'Law and Order: SVU,'" Matlin tweeted. "His passing is truly a loss for Hollywood and I will miss him dearly. RIP Richard Belzer."

Those behind the "Law & Order" cameras also remembered the actor following his passing. "Richard Belzer was the first actor to welcome me when I started at 'SVU,'" tweeted former "SVU" showrunner . "Open, warm, acerbic, whip smart, surprisingly kind.

I loved writing for Munch, and I loved being with Belz." These kind sentiments were also echoed by "SVU" writer Neal Baer, who described the actor as a "comic genius" in a heartfelt post. 

"Law & Order" franchise veteran and "SVU" executive producer Julie Martin paid tribute to actor on shortly after his death was confirmed. "Missing Richard Belzer today," Martin shared. "Working with him on 'Homicide' to 'SVU' has been a hilarious, surprising and always joyful experience. I'm sure he's giving 'em all a lot of laughs upstairs.