PKR president Anwar Ibrahim has expressed his deep sadness over the passing of former Indonesian president BJ Habibie.

"I received the sad news from Indonesia that my close and trusted friend who was also the third president of Indonesia Bacharuddin Jusuf Habibie passed away today."

It was reported that the former president passed away at 6.01pm local time after undergoing intensive treatment since his admission to the Rumah Sakit Pusat Angkatan Darat Gatot Soebroto on Sept 1.

"BJ Habibie was an individual I considered family, and he was very concerned about the suffering I went through while I finished my operation after being freed from prison.

Anwar was referring to an operation he had in September 2004 following his release from prison. He had a spinal operation in Munich and stayed at Habibie’s house while recuperating.

He thanked Habibie and the former Indonesian president’s late wife Ainon for looking after him during that difficult time.

"He was a humble man, with lengthy and intelligent discourse and he was no ordinary politician," recalled Anwar in a Facebook post.

"BJ Habibie spoke from confidence as well as from conscience. This was something unique from a great figure and a great leader who will surely be missed by all parties," said Anwar.

He expressed condolences on behalf of his party PKR.