Jatiya Party Presidium Member Kazi Zafar was admitted at the United Hospital in the capital after he fell sick on Saturday.
He was now undergoing treatment under heart specialist doctor Maminuzzaman.
Talking to the Dhaka Tribune, duty doctor Abdullah Al Mamun said Kazi Zafar was under close observation, refusing to make further comments.
In the evening, BNP acting secretary general Miza Fakhrul Islam Alamgir went to the hospital to see the ailing Jatiya party leader and former prime minister. BNP leader stayed with Zafar for about an hour.
Mirza Fakhrul went to the hospital around 11pm again and talked to Kazi Zafar for about 15 minutes in the presence of BNP vice chairman Abdullah Al Noman.
“We have gone there and inquired about his health,” Mirza Fakhrul told the Dhaka Tribune.
BNP standing committee member Brigadier (retd) Hannan Shah and Islami Oikya Jote leader Abdur Rab Yusufi also went to see Kazi Zafar. Jatiya Party Secretary General ABM Ruhul Amin Howlader also went to see the Jatiya Party leader.