British freelance journalist Alex Josey, 55, who arrived in Malaya in 1948, was served a notice by the Malaysian government this week in 1965 to leave Malaysia within 14 days.
Deputy Prime Minister Tun Abdul Razak said Mr Josey had interfered in the country's internal politics despite being a non-citizen.
Mr Josey, who was close to Singapore Prime Minister Lee Kuan Yew, was regarded by Kuala Lumpur as being biased in the articles he wrote about Malaysia.
Mr Lee expressed regret at the move to expel him, calling it an attempt to intimidate the Singapore Government.
"The mailed fist was shown at us, not against Alex Josey," said Mr Lee at an election rally in Fullerton Square. "I can still go on without Alex Josey. Do they suggest that Alex was the man who thought of a Malaysian Malaysia? He was just my channel. I speak for myself and I take the responsibility."
Singapore Deputy Prime Minister Toh Chin Chye also commented on the expulsion, saying it was not a good sign for the People's Action Party, as it showed that Malaysia's central government has been swayed by extremists.
Mr Josey, the first foreign correspondent to be kicked out of Malaysia, left Singapore for London on July 20 but returned soon after it became independent.
He was Mr Lee's press secretary for 10 years and wrote a biography of Mr Lee. He died in Singapore in 1986, aged 76.
Ho Ai Li