An elderly white supremacist accused of shooting dead a guard at the US Holocaust Museum in Washington last year died Wednesday in a hospital near the jail where he was being held, a federal prisons official said.

"Authorities at the location where James von Brunn was incarcerated, the federal correctional complex at Butner, North Carolina, told us that he was pronounced dead at a local hospital shortly before 1:00 pm today," Edmond Ross, a spokesman for the Federal Bureau of Prisons, told AFP.

"He had a long history of poor health, which included chronic congestive heart failure and sepsis," Ross said, although he was unable to state the precise cause of von Brunn's death.

A.J. Kramer, a public defender who was appointed to represent von Brunn in court, confirmed that the 89-year-old had died in hospital.