According to the officials the guards at Kashimpur Central Jail detained the five passengers, all members of an expatriate Bangladeshi family, for a brief period but the pilot, reportedly a retired air force officer, flew away with the plane after sensing his mistake.
"This happened by mistake but the incident made us concerned as there are intelligence reports that terrorists could launch attacks to free militant inmates from this jail," said Inspector General of prisons Brigadier General Syed Iftekhar Uddin.
The prison chief said the helicopter service management apologised for the mistake and the passengers were freed after brief interrogation and allowed to join the wedding reception at a nearby village.