As the purported video of the minister's gun-wielding act went viral, he said his intention was not to harm the feline, but to scare it away.
Mr Mahajan had yesterday visited the house of Dipali Jagtap, who was killed by the leopard in Chalisgaon Tehsil in Jalgaon district, located over 400 km from Mumbai.
While the senior BJP leader was returning after offering condolences to the family, an information reached him that a leopard was sighted near Navegaon locality of Warkhede village.
In the video, which has been widely circulated and also being played by several television news channels, the state medical education minister is purportedly seen participating in the search operation with the pistol in his hand.
Mr Mahajan said the leopard was sighted around 400 feet from his convoy and that he joined the forest department officials and police personnel in the search.
"My intention was not to kill the leopard, but to fire in the air, if needed. I took out the gun for which I have a license," he said in reaction to the controversy. The team, however, could not trace the animal.
"We were told that Forest Minister Sudhir Mungantiwar had permitted shooting of the animal at sight for killing people," Mr Mahajan said.
The leopard has killed five people in the district in the past one-and-a-half months, the minister said. "On Monday, I visited the families of the people killed by the leopard. On my way, the forest officials sighted the leopard, so we decided to chase it," he said.
"Till date, I have not even killed a sparrow," Mr Mahajan said. Meanwhile, NCP spokesperson Nawab Malik said Mr Mahajan should be sacked and an offence must be registered against him for allegedly flouting forest and wildlife laws.
This is not the first time the gun-toting minister has courted controversy. In March 2015, Mr Mahajan was seen at a school function armed with a gun. He later clarified that he carried the weapon for "self-defence" and that he had not been involved in any kind of violence.
Mr Mahajan had tucked the gun at his waist when he arrived at the function attended by differently-abled school children in Jalgaon.
The BJP leader did not have police protection at that time, but there were several police officers from the district with him on the dais.
"It was my licensed gun and I have been carrying it for the last 20 years. I regularly renew my license," he had said.