Dinesh Kumar and Deepak, both 25, were arrested for the murder of Nagender Yadav on the intervening night of May 15 and 16, they said.
Yadav was admitted to Sanjay Gandhi Hospital with bullet injuries on May 16 and succumbed to his injuries at the RML hospital, where he was later admitted.
The victim's wife Bindu said Dinesh, Deepak and Suresh called her husband and Dinesh fired at him as soon as he opened the main gate of their residence.
"She further stated that accused Dinesh had threatened her husband many times prior to the incident. The other relatives of injured (Yadav) stated that he took the names of Dinesh, Deepak and Suresh on the way to hospital," a senior police official said.
Dinesh and Deepak were arrested yesterday following which the former disclosed his enmity with Yadav.
"He (Yadav) was publicly defaming him (Kumar) as his brother had committed suicide...Apart from this, the deceased was having illicit relation with close relative of Kumar," the official said.