LOS ANGELES -- Tony Sirico, the actor known for his role as Peter Paul "Paulie Walnuts" Gualtieri on "The Sopranos," has died at the age of 79.
The news was shared by his Sopranos co-star Michael Imperioli on his Instagram page.
"It pains me to say that my dear friend, colleague and partner in crime, the great TONY SIRICO has passed away today. Tony was like no one else: he was as tough, as loyal and as big hearted as anyone i've ever known. I was at his side through so much: through good times and bad. But mostly good. And we had a lot of laughs," Imperioli wrote.
"We found a groove as Christopher and Paulie and I am proud to say I did a lot of my best and most fun work with my dear pal Tony," Imperioli's post continued. "I will miss him forever. He is truly irreplaceable. I send love to his family, friends and his many many fans. He was beloved and will never be forgotten. Heartbroken today."
Fr. Robert Sirico, Tony's brother, confirmed his death in a Facebook post. Tony Sirico left behind two children, Joanne Sirico Bello and Richard Sirico, "grandchildren, siblings, nieces, nephews and many other relatives," according to his brother.
"The family is deeply grateful for the many expressions of love, prayer and condolences and requests that the public respect its privacy in this time of bereavement," Robert Sirico wrote.
Sirico appeared in each season of "The Sopranos," playing a loyal mobster to Tony Soprano. Sirico played the wisecracking confidant during the show's entire run from 1999 to 2007. The character became a fan favorite for his wisecracks and trademark hairdo.
Sirico also appeared in the mob film "Goodfellas."
Following the end of "The Sopranos," Sirico continued to act and guest star on other shows, including a mini-arc on the animated sitcom "Family Guy" where he portrayed talking dog, Vinny.
ABC News contributed to this report.