Rudolph Isley, one of the founding members of the popular US R&B group the Isley Brothers, has died, the band announced Thursday. He was 84.

"Heaven has gained another angel," the Isley Brothers said in a post on Instagram. "Our hearts are heavy as we announce the passing of our beloved brother Rudolph Isley."

The statement did not say the cause of death or when he died.

Rudolph Isley was born and raised in Cincinnati, Ohio, in 1939.

The band was founded in the mid-1950s when Rudolph and his brothers started a gospel quartet as teenagers.

Their first major hit, "Shout!" was released in 1959. More hits followed: "Love The One You're With," "Testify" and "Between the Sheets."

In 1970, the Isley Brothers earned a Grammy for their popular song "It's Your Thing."

Rudolph, who was known for wearing hats and fur-lined clothing, left the group in 1989 to become a Christian minister.

In 1992, he was among the Isleys inducted into the Rock and Roll Hall of Fame.

Earlier this year, Rudolph sued his brother Ronald over the group's trademark rights.

"We will miss our brother but we know he's in a better place," the group's statement read. "Forever in our hearts."

Rudolph Isley is survived by his wife Elaine, according to broadcaster ABC.