Mexican authorities exhumed a relative of drug kingpin Heriberto Lazcano and took DNA samples from the corpse to remove any doubt they had killed the Zetas leader.

Lazcano, one of Mexico's most wanted men, is believed to have been killed at a baseball field in the northern state of Coahuila on October 7, but the cartel leader's body was stolen from a funeral home by gunmen hours later.

Mexican officials had identified Lazcano with pictures and fingerprints taken at the funeral home, but authorities announced last week that they had decided to exhume one of his parents' bodies to put to rest any doubts.

Forensic experts exhumed a body on Monday in San Francisco cemetery, south of the city of Pachuca in the central state of Hidalgo, as police kept curious onlookers at bay.

A source in the federal prosecutor's office declined to say which relative had been exhumed.

"While the fingerprints and photos did not leave room for any doubts, the (identification) process is also being carried out with a DNA lab study," the source said on condition of anonymity.

Founded by military deserters, the Zetas are one of the most powerful gangs in a drug war that has claimed an estimated 60,000 lives in the past six years.

Lazcano was accused of masterminding the arson attack on a casino last year in the northeastern city of Monterrey that left 52 people dead.

He was also blamed for the killing for 72 migrants found with their hands tied in the northeastern state of Tamaulipas, which borders the United States, in August 2010.

One of two main leaders of the Zetas cartel, Lazcano had a $2.6 million reward on his head. The United States had set its own award at $5 million.

The Zetas are engaged in a brutal turf war with the Pacific region's Sinaloa Cartel, led by fugitive billionaire Joaquin "El Chapo" (Shorty) Guzman, Mexico's public enemy number one and a billionaire criminal who escaped from a maximum security prison in 2001.

The new top Zeta, Miguel Angel Trevino, will have to consolidate his leadership position while at the same time facing a furious offensive from their western rivals.

Trevino, 40, an ex-police officer also known as "Z-40" or "El 40," had been effectively running the Zetas for months, according to experts.

Guzman launched an offensive against the Zetas earlier this year focused on Nuevo Laredo, a northern border town that is the transit point for 40 percent of all Mexico's overland exports into the United States.

The Zetas were founded by Mexican special forces soldiers who deserted and went to work for the Gulf Cartel as enforcers.

They eventually broke with their employers and struck out on their own, adding protection rackets, human trafficking, prostitution and kidnapping to their core drug smuggling business.

The Gulf Cartel has now joined forces with the Sinaloa Cartel, its former foe.

The Zetas are known for decapitating and dismembering their enemies, a shock tactic soon adopted by their rivals.

[Image via Agence France-Presse]