KUALA LUMPUR (Reuters) - Former Malaysian Prime Minister Mahathir Mohamad was discharged from hospital on Monday, his aide said, after the 99-year-old had been admitted earlier this month because of coughing due to a lower respiratory infection.

Mahathir, who served as prime minister for more than two decades, has a history of heart problems and has been in and out of hospital several times in recent years.

Because of his admission to the National Heart Institute on Oct. 15, Mahathir had been unable to attend a court hearing on a defamation case he had filed against the country's deputy prime minister.

Mahathir will attend the court proceedings on Tuesday, his aide said.

(Reporting by Rozanna Latiff; Editing by John Mair)