Authorities have gathered "compelling" evidence against the main suspect in the murder of Mexican rights activist Marisela Escobedo, the governor of the northern state of Chihuahua said in response to doubts raised by the slain woman's son.

In statements to reporters Thursday, Cesar Duarte slammed remarks made by Escobedo's son, Juan Frayre Escobedo, who said the day before that the man accused of the December 2010 murder, Jose Enrique Jimenez Zavala, is a "scapegoat."

"The truth is I see a great deal of ungraciousness in the position he's taken" since authorities announced Jimenez Zavala's arrest, Duarte said, adding there are "many, many elements that clearly show" the suspect committed the murder.

Chihuahua authorities presented Jimenez Zavala this week as the alleged perpetrator of the crime, but the activist's son said "he may have been pressured into confessing to something that isn't true."

According to the Chihuahua state Attorney General's Office, Jimenez Zavala confessed that he killed Escobedo - slain while demanding justice for the murder of her daughter - as part of a deal between the La Linea gang and the Los Zetas drug cartel.

The suspect told investigators that Sergio Barraza, the suspected killer of Escobedo's daughter, Rubi Marisol Frayre, was working for Los Zetas in Zacatecas state and the activist's protests were garnering too much press coverage.

Escobedo was shot and killed in Chihuahua city in 2010 while picketing in front of government offices in the Chihuahua state capital to demand authorities arrest Barraza.

Barraza, Rubi's former boyfriend, was acquitted in a 2010 trial due to a lack of evidence, but an appellate court subsequently overturned that decision and found him guilty, though he remains at large.

Frayre Escobedo, who fled to the U.S. city of El Paso after receiving death threats, said Jimenez Zavala was a "scapegoat" and that a U.S. citizen is the "real killer."

"My mother's brother was a witness to (Escobedo's) murder and denounced (the killer) to the Attorney General's Office. We know he's an American."

He did not reveal the identity of the purported killer and only added that he may be living in the Mexican border city of Ciudad Juarez or in El Paso, Texas.

The governor refused to "enter into a discussion," but said there are "many interests" at play even in the "family sphere." "I insist there those who don't want problems to be solved because they live from them."

In the wake of Escobedo's murder, family members began receiving death threats in Ciudad Juarez and seven of them decided to flee the country and request asylum in the United States.

Four of them have already been granted asylum while the other three are awaiting a decision on their request. EFE