Oscar Osvaldo Garcia Montoya, the suspected leader of the La Mano con Ojos gang, tells Mexico state Attorney General Alfredo Castillo in a video released by prosecutors that he planned to kill him because he believed the official had betrayed him after supposedly taking a pay-off.

"I would have killed you, I would have found you and cut you into pieces," Garcia Montoya told Castillo, who questioned the gang leader following his arrest last week.

Garcia Montoya confessed to participating in 300 murders and ordering 600 other hits.

The gang leader told the AG that he felt betrayed after an unidentified emissary took Castillo $400,000 to seal a supposed deal.

Garcia Montoya acknowledged that the emissary lied and told him he had handed over the money and documents to Castillo.

The man was murdered once the truth came out, the gang leader said.

"That stuck in my head, and that's why I took it personally against you," Garcia Montoya told Castillo.

"I would have found you, I would have killed you, I would have found you and I would have cut you into pieces," Garcia Montoya said in response to a question about what would happened if he had not realized that his emissary had stolen the money intended for the pay-off.

Garcia Montoya said he worked for Beltran Leyva cartel boss Arturo Beltran Leyva until his death in December 2009, later going to work for gunman Edgar Valdez Villarreal and Gerardo Alvarez Vazquez.

Valdez Villarreal, known as "La Barbie," and Alvarez Vazquez have both been arrested.

La Mano con Ojos is based in the central state of Mexico, which surrounds the Federal District and forms part of the Mexico City metropolitan area, Garcia Montoya, who claims to have served in the marine corps and as a police officer, said.

"I was trained to kill," Garcia Montoya says during his videotaped interrogation, adding that he took courses on explosives and military tactics.

The videotaped interrogations of suspected criminals are often made public in Mexico, with many of the subjects freely confessing to the crimes they committed.

La Mano con Ojos controls drug dealing in Huixquilucan, located in the Mexico City metropolitan area, officials said.

The gang, known for beheading its enemies, has been fighting for control of the drug trade in the cities of Naucalpan, Atizapan, Tultitlan, Cuautitlan Izcalli and a section of the capital.

A total of 18 men and two women have been killed by the gang in Mexico state since November 2010, officials said.

A man's headless body was left hanging off the Paseo Interlomas bridge in Huixquilucan, one of the wealthiest cities in Mexico state, on Monday.

The body was strung up by the legs and the head was left inside a trash bag on the bridge, Huixquilucan police chief Gerardo Oyervides told Efe.

"A sign with a message supposedly signed by the La Mano con Ojos criminal organization was found" on the bridge, the police chief said.