An upcoming book reveals that the man known as Subcommander Marcos, who entered the international spotlight as the spokesperson for a Mexican indigenous rebel group in 1994, had been suffering from lung cancer as recently as 2010.

The Mexican newspaper Milenio reported Wednesday that it had obtained an excerpt from the book, written by Luis H. Alvarez, the federal official who coordinated negotiations between the government and Marcos' group, the Zapatista Army of National Liberation (EZLN).

In the book, Alvarez says a representative from Chiapas, the Mexican state where the EZLN is based, told him about Marcos' illness. Alvarez also said the official, Jaime Martínez Veloz, confided in him that Marcos was asking for help from the federal government in treating the disease.

Alvarez also wrote that Marcos was troubled by the fact that many of the communities supporting the EZLN still suffered from high poverty, leading to many of the indigenous members deserting its' cause. The excerpt does not include speculation on what Marcos' death in this setting would mean to the movement, or if the group had a plan of succession in place.

Last year, Marcos, an avid smoker, denied rumors he was suffering from lung cancer in a release, though he noted, "hearing about pulmonary emphezema and cancer led to me not getting tobacco, which is a clear counter-insurgency maneuver. So it's official. I don't have what they say I have ... at least, not yet."

Neither Marcos, who has never revealed his identity - various media outlets have speculated him to be 57-year-old Rafael Sebastián Guillén Vicente- nor the EZLN has responded to Alvarez's allegations, but the state official he spoke to, Jaime Martínez Veloz, denied at least one of them on Twitter.

"In 18 years, I have never known about a request of any kind from the EZLN toward the federal government," Veloz tweeted, in a distilled version of a statement he released saying that, though he did share his concerns about Marcos' health with Alvarez, he said he could not confirm that he had cancer.

Marcos and the EZLN, which sees itself as the spiritual heir to former Mexican president Emiliano Zapata, have been at odds with the government since New Year's Day in 1994, when it protested the North American Free Trade Agreement between Mexico, the U.S. and Canada and seized a number or Chiapas town, prompting a brief series of armed skirmishes against the national army. The group has since formed several autonomous municipalities within Chiapas.

[File photo of Subcommander Marcos circa 2006 via GeneralZapata on Wikipedia Commons]