Stewart died on Monday night, Sanef said in a statement.
“Sanef members mourn the loss of their loved colleague and founder member.
“He was an energetic member of Sanef from its inception, supporting Sanef ideals and contributing his time to ensure Sanef policy was in line with its journalistic ideals of quality and accuracy,” it said.
Sanef veteran member Raymond Louw said Stewart made an enormous contribution to newspapers and newspaper journalism.
He made a contribution as reporter, editor, lecturer in journalism and head of the journalism department at Rhodes University.
“He contributed to the maintenance and promotion of high professional standards of newspaper journalism…
“His sage and well-balanced advice always made an impact on other journalists and members of Sanef,” Louw said.
Stewart was a reporter and journalist at a number of newspapers including the Natal Witness, Golden City Post, Sunday Times and the Rand Daily Mail.
He was also a former editor of the Daily Dispatch.