Former Playboy playmate Ashley Mattingly has died at the age of 33, according to multiple reports.

The model, who lived in Austin, Texas, was found unresponsive on Thursday, according to her sister Christy Deweese and twin brother Billy, who told People that Mattingly died of apparent suicide and had left behind a note.

"We learned late Thursday night that it is believed that our dear sister with a larger-than-life personality took her own life,” the family said in a statement. “Ashley moved closer to home a couple years ago and was living in Austin. It's maybe no secret that Ashley struggled with alcohol and substance abuse, but she wanted to and was working to get better."

According to the siblings, their sister, who was recognisable as Playboy’s Miss March in 2011, was found in her home on 16 April after a friend called police for a wellness check.

Christy and Billy have since taken in Mattingly’s golden retriever puppy, which she had recently adopted to “overcome these demons”.

“She will continue to live on through nieces whom she loved dearly and always thought of no matter how far away she was, a twin brother, two sisters and numerous other friends and family members,” the statement continued. “We will forever cherish her memories and know that her joy is eternally sealed. We look forward to seeing her again.”

The family concluded the statement expressing their hope that their sister’s story can “continue to shed a light on suicide awareness and prevention”.

On Facebook, the siblings also paid tribute to their sister, with Christy calling Mattingly the “most gorgeous angel in heaven”.

“Because I can't find the words to say I will just leave this here,” she wrote. “I love you and will miss you every day. Fly high sister, I know you are the most gorgeous angel in heaven!”

On Billy’s Facebook page, he described his twin sister as a "rock star" and "beauty queen,” before asking friends and families to leave memories in tribute.

Others, including fellow former playmates, have also expressed their condolences for Mattingly's passing on social media.

“I am devastated. My friend #ashleymattingly took her own life,” Carrie Stevens tweeted. “If you are struggling please reach out for help. She was only 33 RIP #playmatesister.”

Playboy model Tiffany Toth shared a picture of Mattingly and wrote: “May you RIP @AshleyMattingly. I’m not very good with words when it comes to things like this, but I’m so sorry.”