Christopher Meloni, Dick Wolf, Ice-T and Others React to SVU Star Richard Belzer's Death

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Richard Belzer is being remembered by peers and fans as "whip smart," a "challenger of power" and "one of the funniest people ever."

The longtime comedian and Law and Order: Special Victims Unit has died at age 78, former Late Show with David Letterman writer Bill Scheft confirmed to The Hollywood Reporter on Sunday.

After the news of his death quickly spread, costars and friends shared their memories of the man known for inspiring laughs both as a comedian as well as playing beloved detective John Munch in the series from 1999 to 2016.

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RELATED: Richard Belzer, Law & Order: SVU Star, Dead at 78

"I'm so sad to hear of Richard Belzer's passing," actress Laraine Newman, who was among the first to pay tribute, wrote on Twitter.

"I loved this guy so much. He was one of my first friends when I got to New York to do SNL," she shared. "We used to go out to dinner every week at Sheepshead Bay for lobster. One of the funniest people ever. A master at crowd work. RIP dearest."

Some of Belzer's SVU costars and co-workers also paid tribute to the actor, who originated the role of Munch on NBC's Homicide: Life on the Street in 1993 and reprised the character in the Law & Order parent series.

During his time as Munch, he later appeared in nearly 330 episodes of SVU between 1999 and 2013, with two additional cameos in 2014 and 2016.

"Richard Belzer was the first actor to welcome me when I started at SVU," wrote showrunner Warren Leight. "Open, warm, acerbic, whip smart, surprisingly kind. I loved writing for Munch, and I loved being with Belz. We sensed this would be his parting scene. Godspeed Belz."

After news broke of Belzer's death, SVU star Christopher Meloni shared a sweet photo of Belzer to Twitter.

Fellow SVU star Mariska Hargitay shared some words on social media herself, calling Belzer a "dear friend."

"I will miss you, your unique light, and your singular take on this strange world," Hargitay, 59, 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."

Diane Neal also shared a tribute to her former costar. "my hero. We always had fun. Genuinely. At work. On vacation. Anywhere," Neal wrote. "The man who made every moment better. I will miss you terribly."

Alongside a throwback SVU photo, Jon Seda applauded Belzer's life and career. "[Belzer] was one of the best ever to grace our screens. I learned so much from him. Forever in our hearts he'll remain. RIP friend," Seda wrote.

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Danny Pino shared an emotional note to the SVU alum, too. "You…made me laugh. welcomed me. emboldened me. showed me how precious, beautiful and ridiculous it all is. taught me to hit a speed bag. made me a Rolling Stones fan. taught me grace. opened your home. gave back. made me laugh. made us laugh. l… Love you, Belz," Pino captioned a photo of Belzer.

SVU costar Ice-T posted to Instagram: "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 🙏"

S. Epatha Merkerson also called Belzer, "one of a kind" in her own tribute.

Dick Wolf, creator and executive producer of SVU, wrote in a statement shared with PEOPLE that Belzer's Munch is "one of television's iconic characters."

"I first worked with Richard on the Law & Order/Homicide crossover and loved the character so much, I told Tom [Fontana] that I wanted to make him one of the original characters on SVU," Wolf, 76, wrote. "The rest is history. Richard brought humor and joy into all our lives, was the consummate professional and we will all miss him very much."

Dean Winters, another SVU costar and law enforcement partner on the series, said Belzer was instrumental in his being cast. "Everyone can have water, not everyone can have class. Richard Belzer had class for days. I will miss this man very much," he said in part.

Other acting highlights from Belzer's career include his role as a Babylon Club M.C. in the 1983 film Scarface, his role as the president in the 1998 film Species II, and The Flash TV series in 1991.

The funnyman also had a much-lauded comedy career, and was vocal about his belief in various conspiracy theories, having written a selection of books on those subjects as well.

Friend and fellow comedian Paul Shaffer said in a statement shared with PEOPLE: "Since we met in the mid-1970s, an evening with Richard Belzer was an evening reserved for laughs."

"As a stand-up, he presaged the comedy explosion still felt in entertainment today," Shaffer added. "And although he had seamlessly transitioned to serious acting, 'Belz' remained the standard bearer with regard to what was funny. Everyone should have a best friend who makes you laugh that hard."

"Missing Richard Belzer today," wrote SVU writer and executive producer Julie Martin. "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."

Actor Michael Warburton also shared kind words on Twitter, calling Belzer "a stand up guy, a dude, & what I call a real citizen."

"He was so many things - a great Comedian & Wit, an Actor, a Writer (his Work on JFK's assassination was excellent), an Activist, a challenger of authority and the Establishment," Warburton wrote.

He also shared a funny moment from The Green Room in 2011 where Belzer takes part in a "Jagger-Off" — or a competition of Mick Jagger impressions — with comedian Rick Overton.

Saturday Night Live writer and longtime friend Alan Zweibel gave Belzer praise, calling him "as kind as he was funny" in his Twitter tribute on Sunday.

"I will miss his brand of comedy that was not confined to boundaries," he wrote. "And will always be grateful for a friendship that lasted almost 50 years."