A little-known member of one of rock 'n' roll's royal families, Benjamin Keough, grandson of the late Elvis Presley and only son of the "The King's" daughter, Lisa Marie Presley, has died at age 27, her spokesman said on Sunday.

There was no immediate word from authorities on the circumstances or timing of Keough's death. The Los Angeles County coroner's office confirmed only that the death of an individual of his name and age was under investigation.

Citing unnamed law enforcement sources, celebrity news website TMZ said Keough had taken his own life on Sunday in Calabasas, California, a community northwest of Los Angeles. That information could not be independently verified.