(NEXSTAR) – Bill Cosby, who portrayed Malcolm-Jamal Warner’s TV dad on “The Cosby Show,” is mourning the loss of the 54-year-old actor after his tragic death on Sunday.

Warner was vacationing with family in Costa Rica when an ocean current pulled him away from the shore while swimming at Playa Grande de Cocles in Limon. Costa Rica’s Judicial Investigation Department reported that other beach-goers retrieved Warner from the water, but medical responders could not make out any vital signs.

Speaking with ABC News, Cosby fondly remembered his time with Warner.

“He was always a great studier, and I enjoyed working with him very much,” Cosby told the outlet, adding that Warner “always” knew his lines and was prepared for their scenes.

Malcolm-Jamal Warner as Theodore Huxtable and Bill Cosby as Dr. Heathcliff Huxtable are pictured during a 1985 episode of “The Cosby Show” called “Theo and the Older Woman.” (Photo by NBCU Photo Bank/NBCUniversal via Getty Images via Getty Images)

Cosby also told ABC News that Warner called him “regularly.” Cosby’s agent Andrew Wyatt claimed in a statement to TMZ and USA Today that Warner had last contacted Cosby ahead of a performance at a venue in Minneapolis several weeks ago.

Wyatt added that Warner’s death reminded Cosby of the death of his own son, Ennis, who was killed in 1997 during a failed robbery attempt. Cosby’s interactions with Ennis inspired the character of Theodore Huxtable, played by Warner on “The Cosby Show.”

Cosby, 88, has become a controversial figure since leaving TV, having been accused by multiple women of sexual assault. He was sentenced to prison in 2018 for drugging and sexually assaulting Temple University employee Andrea Constand, but he was released in 2021 when his conviction was overturned on a technicality.

Cosby has maintained his innocence.

In addition to Cosby, several of Warner’s friends and co-stars have shared their condolences on his passing, including Eddie Griffin, who starred alongside Warner on “Malcolm & Eddie,” and Tracee Ellis Ross, who starred with Warner on “Reed Between the Lines.”

“I love you, Malcolm. First I met you as Theo with the rest of the world then you were my first TV husband,” Ross wrote on Instagram. “My heart is so, so sad. What an actor and friend you were: warm, gentle, present, kind, thoughtful, deep, funny, elegant. You made the world a brighter place. Sending so much love to your family. I’m so sorry for this unimaginable loss.”