Attending doctors said 72-year-old Chowdhury is diabetic and a patient of a serious cardiac ailment.
He was admitted yesterday and shifted to the intensive Care Unit (ICU) following cardiac problems, sources said.
He was arrested on Friday for his alleged involvement in the triple killing, and was remanded the next day to three days judicial custody.
When a bail petition was moved by his lawyer Pijush Biswas at the court of Chief Judicial Magistrate B Palit yesterday, the Assistant Public Prosecutor pleaded for seven days police custody.
The driver of the editor's vehicle, Balaram Ghosh, manager Ranjit Choudhury and proof reader Sujit Bhattacharjee were killed inside 'Dainik Ganadoot' building on May 19.