By Faisal Mohammad Ali
BBC News, Bhopal
Khan's condition has shown a little improvement now (Photo: Prakash Natvalne)
Three employees of an event management firm in India have been arrested for putting the life of a reality TV show participant in danger, police say.
Anjar Khan, 22, took part in the show in the central Indian city of Indore where contestants were asked to stay under water for as long as possible.
He collapsed and is in hospital in a "serious condition", doctors say.
Reality TV shows have become huge hits in India with thousands queuing up to take part in them.
Mr Khan participated in a programme at a shopping mall in Indore on Sunday to publicise a new reality TV show "Khatron Ke Khiladi" [Dare devils] where participants were dared to remain under water in a huge glass tank.
He was inside the water tank for some minutes before the organisers realised there was something wrong and he was pulled out.
Reports say he lost consciousness in the tank and had water in his lungs.
He managed to walk a few steps but then collapsed. He was taken to a nearby hospital where he has been on artificial respirator ever since.
"He was brought to the hospital with a major part of his system such as pulse and blood pressure in an extremely critical condition," Dr GMR Shah of Mayur Hospital told the BBC.
Dr Shah said Khan would continue to be on ventilator for some more days although his condition had shown some improvement.
According to reports, no doctors or paramedics were present at the mall when the incident took place.
Officials say the organisers did not have permission to hold the contest.
Senior police officer Mahesh Chandra Jain said the arrested employees would be charged with "gross negligence which put a person's life in danger".