Kassim’s son Ahmad Shauqi confirmed that his father was hospitalised for a lung infection and a blocked heart valve on Sept 16.

The Malay Mail Online quoted Shauqi as saying last night that his father had difficulty breathing and was using an oxygen mask.

He rushed to the hospital to see his father after his sister in Kulim called him in Penang and informed him his father was in critical condition.

Shauqi said he was upset with the religious authorities for the strain imposed on his elderly father who had faced charges that he had insulted Islam and defied the religious authorities.

The Shariah High Court later acquitted and discharged Kassim after ordering the withdrawal of the charges.

“I’m going to make sure the lawyer who defended my father sues them — giving him all this trauma,” Shauqi said.

“He’s a learned man and he’s not a violent man. He’s a very calm person, but sad what society has done to him.”

He also said that his family was praying hard for Kassim.

“He has so much to offer. He sacrificed his life for the people.”

Kassim is best known for his work Hadith: A Reevaluation, a critical study on the authority of the Hadith as a source of Islam.