The brawl at the Chhatrasal Stadium that allegedly led to the death of a former junior national wrestling champion was the result of a conspiracy hatched by Olympic medallist wrestler Sushil Kumar, who wanted to re-establish his supremacy among younger wrestlers, the Delhi Police has said in its charge sheet filed in the murder case.

There were "murmurs" that Kumar was scared of the two tenants living in a house he owned and he "nursed a deep grudge" about the loss of respect in the eyes of his students, it said.

Kumar and his associates allegedly assaulted 23-year-old wrestler Sagar Dhankar, his friend Sonu and three others at the stadium on the intervening night of May 4 and 5 over a property dispute. Later, Sagar succumbed to his injuries.

"The present incident is the result of a criminal conspiracy hatched by accused Sushil Kumar along with his associates to take revenge from Sonu and Sagar," the police said in its over 1,000-page charge sheet filed on Monday.

The Crime Branch, which is tasked with investigating the case, said Kumar wanted to teach a lesson to Sagar and Sonu and re-establish his supremacy in the stadium through muscle power. It also listed reasons why Kumar and his associates took revenge.

The police investigation established that it was due to the initial reluctance shown by Sagar and Sonu to vacate Kumar's flat and "murmurs" in the stadium that the Olympic wrestler was scared of the duo and couldn't withstand them.

Another reason, according to the police, was that Kumar had a strong suspicion that wrestlers training under him were passing information about his movements to Sagar and Sonu and the latter could harm him as he had an extensive criminal background.

"When he realised that some of his own trainees were passing information about him to Sonu and Sagar, he felt betrayed and thus nursed a deep grudge against Sonu and Sagar for loss of respect in the eyes of his students," the charge sheet stated.

Notorious criminal Kala Jathedi, who was recently arrested, told the police that Kumar's ego was hurt after Sagar and Sonu refused to vacate his flat because of which he felt a loss of respect.

The charge sheet names 13 accused, including Kumar, who is named as the main accused.

The police said they relied on the oral dying declaration of Dhankar, scientific evidence including locations of the accused, CCTV footage, weapons and vehicles recovered from the spot.

"From the material collected during the investigation so far precisely mentioned above, there is sufficient material against the accused persons," it stated, seeking their prosecution under 22 offences of the Indian Penal Code.

The charge sheet mentions the names of 155 prosecution witnesses, including four persons who were injured during the brawl.

The Delhi Police had filed the FIR against the accused for offences such as murder, attempt to murder, culpable homicide, criminal conspiracy, kidnapping, robbery and rioting, among others.