Edmond Harjo, one of the last remaining Native American code talkers, has died. He was 96.

The Swearingen Funeral Home says Harjo died March 31 at Mercy Hospital in Ada. Harjo's nephew, Richard Harjo, says his uncle had a heart attack.

Harjo was a member of the Seminole Nation of Oklahoma. He was also one of the last surviving members of a group of American Indians who used their native languages to outwit the enemy and protect U.S. battlefield communications during World Wars I and II.

Harjo traveled to Washington D.C. last November to take part in a ceremony where congressional leaders bestowed the Congressional Gold Medal, its highest civilian honor, on American Indian code talkers.

A funeral service was held for Harjo on April 4.

His nephew said one of his uncle's last moments was recalling his favorite song called, "The Little Church in the Wildwood," The Native American Times reported. The song was played during the funeral service.

The Associated Press contributed to this report