A leader of a Mexican fuel theft gang has been shot dead while undergoing plastic surgery to change his identity by removing his fingerprints and changing his face.

Gunmen from a rival gang burst into the clinic in the city of Puebla and killed Jesus Martin, known as El Kalimba, along with three other people, Puebla state prosecutors confirmed.

“He was trying to change his identity with a series of plastic surgery procedures to alter his face and remove his fingerprints so he couldn’t be identified,” prosecutors said in a statement.

“The medical personnel involved are also being investigated.”

Police confirmed the murder was over a dispute between rival gangs. They police also mentioned Jesus Martin had been running an operation siphoning fuel from pipelines illegally.

Siphoning fuel has become a risky but lucrative business that is now Mexico’s second-biggest organized crime problem after drug trafficking.

Fuel thieves drill an average of 28 illegal pipelines every day in Mexico.

State authorities have said the gang fighting has occurred in part because of a huge police crackdown that has made it harder to steal fuel.