Gesine Bullock-Prado, the sister of Sandra Bullock, paid tribute Monday to the actress's longtime partner, photographer Bryan Randall.

Randall "passed away peacefully" following a private three-year battle with ALS, his family said in a statement to People magazine. He was 57.

Bullock-Prado is a celebrity chef and posted a photo of Randall on her verified Instagram account, writing, "I'm convinced that Bry has found the best fishing spot in heaven and is already casting his lure into rushing rivers teaming with salmon."

"ALS is a cruel disease but there is some comfort in knowing he had the best of caretakers in my amazing sister and the band of nurses she assembled who helped her look after him in their home," she wrote. "Rest in peace, Bryan."

Randall and Bullock went public with their relationship in 2015. CNN has reached out to reps for the actress for comment.

"Bryan chose early to keep his journey with ALS private and those of us who cared for him did our best to honor his request," his family said in their statement. "We are immensely grateful to the tireless doctors who navigated the landscape of this illness with us and to the astounding nurses who became our roommates, often sacrificing their own families to be with ours."

The family asked for privacy to grieve and requested that in lieu of flowers donations be made to the ALS Association and Massachusetts General Hospital.

Amyotrophic lateral sclerosis, more commonly known as ALS, is a progressive, neurodegenerative disease that affects nerve cells in the brain and spinal cord.

Bullock-Prado echoed the request for donations to the ALS Association in her post.

Her sister, who is known for being a private person, talked about her relationship with Randall during a 2021 appearance on "Red Table Talk."

"I found the love of my life. We share two beautiful children -- three children, [Randall's] older daughter," Bullock said. "It's the best thing ever."

Bullock is mother to a 13-year-old son, Louis, and a 10-year-old daughter, Laila. Randall was the father of an adult daughter named Skylar.