(Image credit: Andrew H. Walker/Getty Images)

Robert F. Kennedy, Jr. has reportedly been dating actress Cheryl Hines, best known from the TV show "Curb Your Enthusiasm."

On Wednesday, Kennedy's estranged wife Mary Richardson Kennedy died at age 52 apparently from committing suicide by hanging herself, multiple sources told ABC News.

Kennedy and Hines have been romantically linked since last year and were photographed in January attending the Sundance Film Festival in Utah. Kennedy's daughter Kathleen "Kick" Kennedy, an aspiring actress, was also seen with the couple.

Kennedy, a prominent environmental lawyer, is the son of the late Sen.  Robert Kennedy and the nephew of President John F. Kennedy. He is the vice chair and chief prosecuting attorney for the Riverkeeper, an environmental foundation that advocates for clean water sources in New York.

Hines and Kennedy attended the Riverkeeper's annual Fisherman's Ball in New York City together in April and posed together on the red carpet.

Hines' character on "Curb Your Enthusiasm" is an avid environmentalist and she joked on the red carpet that she was learning to become one in her real life.

"We deeply regret the death of our beloved sister Mary, whose radiant and creative spirit will be sorely missed by those who loved her," Mary Kennedy's family said in a statement released through her lawyer. "Our heart goes out to her children who she loved without reservation."

Mary Richardson Kennedy was Kennedy's second wife and the couple had four children together. The couple was married for 16 years before a divorce filing in 2010.