Lisa Marie Presley's 27-year-old son Benjamin Keough has died, a representative for Presley confirmed on Sunday.

Keough was the grandson of the late rock legend Elvis Presley. According to Presley's representative, Roger Widynowski, the family is reeling from Sunday's sudden and unexpected loss.

"[Lisa] is completely heartbroken, inconsolable and beyond devastated but trying to stay strong for her 11 year old twins and her oldest daughter Riley," Widynowski said in a statement to ABC News. "She adored that boy. He was the love of her life."

The cause of Benjamin Keough's death has not been disclosed.

In 2012, Presley revealed on Twitter that she and Keough celebrated Mother's Day in 2009 by getting matching Celtic eternity knot tattoos. The symbol represents eternal love.

Keough maintained a relatively private life and was rarely photographed by paparazzi. He previously appeared in the 2005 documentary, "Elvis by the Presleys" and, alongside his siblings, appeared in the music video of his mother's 2012 duet with his late grandad, "I Love You Because."

Besides his parents, Presley and musician Danny Keough, Benjamin Keough leaves behind his sister, 31-year-old actress Riley Keough and his 11-year-old twin siblings Harper and Finley Lockwood. The twin daughters were born during his mother's previous marriage to guitarist and producer Michael Lockwood.