The deceased were identified as Saddam Hossain, 21, son of Tozam Hossain, and Russel, 22, son of Korban Ali of the area.
But police and upazila administration officials offered different versions about what had happened.
Kazipur Upazila Nirbahi Officer Jahid Hasan Siddique said Saddam and Russel fell sick after drinking alcohol on Thursday evening. They were admitted to Shaheed Ziaur Rahman Medical College Hospital in Bogura where they died on early Friday.
But AKM Lutfor Rahman, officer-in-charge of Kazipur Police Station, said the young men attended a wedding ceremony at noon and had food but started vomiting at night.
Police recovered the bodies and took them to Bangamata Sheikh Fazilatunnesa Mujib General Hospital morgue in Sirajganj, the UNO said.
Snigdho Akhter, additional superintendent of police (Sadar, Kazipur circle), said the cause of death was unclear.
“It’ll become clear after the autopsy reports come,” she said.