Elvis Presley's grandson Benjamin Keough allegedly killed himself during a birthday party for his girlfriend Diana Pinto.

The 27-year-old is believed to have shot himself in the head after locking himself in the bathroom at his mother Lisa Marie Presley's Californian mansion.

According to the Daily Mail, police were called at around 6am on July 12 and neighbours reported hearing a female voice scream "don't do it!"

Posting a tribute to her boyfriend on Instagram at the weekend, Pinto wrote: "You made me the luckiest girl in the world, to have you, to hold you, to love you and to be loved by you are the only things that have ever mattered.

"You are my whole world and my whole life, you live with me now every day in my heart, in my soul and in my mind. My travel partner. My best friend."

Lisa Marie is said to be "completely crushed" by her son's suicide.