Tabrez Ansari was assaulted by the mob on 18 June, after being accused of breaking into a house and stealing a motorbike in the eastern state of Jharkand.
Several videos, which appear to be of the assault, spread quickly online in the aftermath of Ansari’s death.
One clip allegedly shows members of a crowd beating the man with sticks, according to The Telegraph India.
In another the mob can be heard forcing the 22-year-old to chant "Jai Shri Ram” and “Jai Hanuman”.
The chants, which mean “victory to Lord Rama” and “victory to Hanuman”, are traditionally performed by devout Hindus. Rama and Hanuman are both Hindu gods.
In the video, Ansari can be heard chanting and pleading with the crowd to stop.
The mob subsequently reported the 22-year-old to the police.
Officers who arrived at the scene found him tied to a tree.
Detectives said Ansari admitted to robbing a house with two other men who had escaped, according to The Wire India.
Multiple Indian newspapers said the police officers did not record the alleged assault in their incident report.
Ansari was held in police custody until Saturday, when he said he was feeling ill.
He was taken to hospital in the city of Jamshedpur but was declared dead on arrival, according to The Indian Express.
His family allege he died from having been “mercilessly” beaten for four hours by the mob.
“Let us assume he was caught for theft, but tying him up and beating him for hours and then asking him to chant Jai Shri Ram is shocking,” Maqsood Alam, Mr Ansari’s uncle, said.
“His mistake was that he was a Muslim, otherwise he would have been alive.”
A N Dey, the civil surgeon at Sardar Hospital, said Ansari’s cause of death would be confirmed in a post-mortem but added that he could have died of a “heart attack or blockage”.
Police have arrested one person in connection with the death and an investigation is ongoing.
A recent US government report on international religious freedom found that mob attacks against Muslims in India occurred throughout 2018.
“There were reports of religiously motivated killings, assaults, riots, discrimination, vandalism and actions restricting the right of individuals to practice their religious beliefs,” the document noted.
The Indian government has strongly rejected the report’s findings.
“India is proud of its secular credentials, its status as the largest democracy and a pluralistic society with a longstanding commitment to tolerance and inclusion,” a spokesperson said.