Laura Prepon mourns death of brother Brad Prepon

Laura Prepon has announced the death of her beloved brother, Brad Prepon.

In a message posted to Instagram on Wednesday, the That '70s Show actress shared that her sibling passed away "suddenly" of an "unknown heart condition" on 15 July. He was 48.

"This past weekend, we laid my brother to rest. He passed away suddenly from an unknown heart condition - it was a devastating shock," she captioned a slideshow of throwback photos. "For those of you who knew Brad, I'm so happy he touched your lives. For those who didn't, we lost a singular, beautiful, inimitable force. I will miss my brother every day, and carry him in my heart always."

To conclude the emotional message, Laura urged her followers to make an appointment with their doctor if they are concerned about their health.

"If you feel something may be off, please listen to your instinct and get it checked out," the 46-year-old continued, adding: "Hug the ones you love."

Following the sad news, many of Laura's celebrity friends expressed their condolences.

"I love you, Prepon," commented her Orange Is the New Black co-star Uzo Aduba, while Questlove declared, "Sincere Condolences Laura."

In an obituary, Brad was described as a "remarkable" tennis player and history buff.

"Beneath Brad's polished exterior was an introspective and contemplative seeker. As much as he loved a night out, he was just as happy being lost in a book. Ever the inner alchemist, Brad enjoyed gaining knowledge, incorporating it into his life, and forging his own path," it reads. "Brad will be remembered through the qualities that made him uniquely himself. He was a singular, inimitable force, who touched the hearts of many. He will be truly missed."