Idris Elba has joined the stars of The Wire in mourning the death of Michael K Williams at the age of 54.

The British actor, who played business-savvy Stringer Bell in the acclaimed drama series, simply posted a black square on Instagram, captioned “MKW.”

Williams, who memorably played charismatic shotgun-wielding stick-up man Omar Little, was found dead at his home in Brooklyn on Monday, police in New York said.

No cause of death was given but US media reports suggest it is being investigated as a suspected drug overdose.

A representative confirmed the news, describing the death of Williams as an “insurmountable loss”.

Tributes have flooded in for Williams, who as well as his role on The Wire earned fame and plaudits for playing Albert “Chalky” White on the HBO series Boardwalk Empire.

John Wick star Lance Reddick shared an emotional video of memories of their times together, describing him as “one of the kindest, gentlest, most genuine, giving and courageous souls I’ve ever met”.

He added: “Rest in peace, my brother. Much love and respect.”

Oscar-winning filmmaker Spike Lee, 64, who like Williams grew up in Brooklyn, shared a picture of himself and “my brother” together.

He wrote on Instagram: “Our Brother Passed Away Today In His Home, Da People’s Republic Of Brooklyn. I’m Shook. Drinking A Bottle Of Italian Red Wine-Brunello Di Montalcino By Myself. Our Greats Are Leaving Us Left And Right. God bless.”

Wendell Pierce, 57, starred alongside Williams on The Wire, playing Detective Bunk Moreland.

He wrote a moving Twitter thread and said: “The depth of my love for this brother, can only be matched by the depth of my pain learning of his loss. A immensely talented man with the ability to give voice to the human condition portraying the lives of those whose humanity is seldom elevated until he sings their truth.”

David Simon, creator of The Wire, also paid tribute to Williams.

He posted a picture of the actor to Twitter and wrote: “Too gutted right now to say all that ought to be said. Michael was a fine man and a rare talent and on our journey together he always deserved the best words. And today those words won’t come.”

Isiah Whitlock Jr also starred alongside Williams in The Wire and paid tribute on Twitter.

He said: “Shocked and saddened by the death of Michael K Williams. One of the nicest brothers on the planet with the biggest heart. An amazing actor and soul. May you RIP. God bless.”

One Night In Miami star Aldis Hodge, 34, said he was stunned by the news.

He wrote on Instagram: “I can’t even believe this.

“Rest in power, Mike. You were always a good brother. A fantastic artist and an even better human being. We’ll miss you.”

Chart-topping singer Mariah Carey shared smiling pictures of her and Williams together.

She wrote on Instagram: “A beautiful soul, a beautiful person, I’ll miss you always. Thank you for blessing us with your talent.”

Award-winning actress Kerry Washington said: “So heartbroken. @bkbmg thank you for the beauty and joy you brought to the world. Sending love and prayers to your friends, family and everyone who adored you me included We adore you Sir.”

Oscar-winner Viola Davis said: “No! So sad. Man do I wish this were a different ending. Rest well.”

Hollywood star Mark Wahlberg said: “RIP Michael K. Williams, so brilliant in #BoardwalkEmpire. You will be missed.”

Giancarlo Esposito, perhaps best known for playing drugs kingpin Gus Fring in crime drama series Breaking Bad, also paid tribute to Williams.

He said: “I have never met a more loving, caring, beautiful human being. A true friend and thespian. I will forever miss you my dear brother. Godspeed.”

Aisha Tyler, the actress and director, said Williams was a “beautiful, passionate, expansive soul”.

She tweeted: “I felt so lucky to have known him, and we were all so fortunate to have enjoyed his incredible talent. He burned so very bright. Rest in power, MKW. You will forever be The King.”

Horror writer Stephen King said: “Horrible, sad, and unbelievable to think we’ve lost the fantastically talented Michael K. Williams at the age of 54.”

And veteran actor Colman Domingo tweeted: “Truly gutted on hearing the passing of Michael K. Williams. A tremendous actor.”

In its statement, HBO, the network where Williams became a star, described his death as an “immeasurable loss”.

It said: “We are devastated to learn of the passing of Michael Kenneth Williams, a member of the HBO family for more than 20 years.

“While the world is aware of his immense talents as an artist, we knew Michael as a dear friend who was beloved by all who had the privilege to work with him.

“We send our deepest condolences to his family for this immeasurable loss.”