The four men attacked Kasim Shaikh in public near a market in the Cuffe Parade area of South Mumbai on Friday night over some personal enmity, a police official said.
During the incident, one of the accused spit on his shoe and forced Mr Shaikh to lick it, he said.
Kasim Shaikh managed to free himself from the attackers. But, unable to bear the humiliation, he hanged himself at his residence in the Cuffe Parade area on Saturday morning, the official said.
Based on the suicide note, the police arrested Ismail Shaikh (47), Akbar Shaikh (35), Karia Pavse (35) and Afzal Qureshi (44) on Saturday evening, the official said.
They were charged with abetting suicide, the official said, adding that an investigation was underway.
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