Police have registered a case and ordered investigations to ascertain the actual reason behind the accident.
Four national-level power-lifters have died after being involved in a road accident near the Delhi-Haryana border, while two others were seriously injured.
Yadav, along with five other powerlifters, were travelling from Panipat towards Delhi in their Swift Dzire vehicle, when the auto hit a road divider.
DCP (Rohini) Rajneesh Gupta said the deceased have been identified as Tikamchand alias Tinka (27), Saurabh (18), Yogesh (24) and Harish Roy (20).
Another weightlifter, Rohit, 19, is battling for life.
They have been admitted to Max Hospital in north-west Delhi's Shalimar Bagh. The victims were celebrating a birthday party and some alcohol bottles were found inside the vehicle, police said.More news: Golden Globes 2018: Stars take activists as dates on red carpet
"Saksham's condition is extremely critical as he has severe head injuries".
Police said that they were driving towards Karnal in Haryana after the birthday celebrations of one of the occupants of the auto. Yadav was driving the silver Swift DZire on a highway leading to Karnal, Haryana, and crashed around 4am, police said.
The auto followed through and then hit an electric pole.
From prima facie, it appeared that the auto was being driven at a very high speed and it being probed whether it was a case of drunken driving as some liquor bottles were found in the vehicle.
The impact of the accident was so high that the car's roof was completely blown off, police said. The accident took place when the weightlifters were returning to Delhi.