Hackers have stolen sensitive Mexican files including previously undisclosed information that President Andres Manuel Lopez Obrador was taken to hospital by air ambulance in January with a heart problem, the government said Friday.

"It's true, there was a cyberattack," Lopez Obrador said at his daily news conference.

"I understand that this same group has already done the same thing in other countries," he added.

On Thursday, prominent journalist Carlos Loret de Mola reported that a hacker group called Guacamaya had obtained tens of thousands of emails dating from 2016 to September 2022 from the .

The files revealed that Lopez Obrador, 68, was taken by air ambulance on January 2 from his ranch in Palenque, in the southern state of Chiapas, to be treated at a military hospital in Mexico City, Loret de Mola said.

"Everything that is said there is true," Lopez Obrador, who suffered a heart attack in 2013, told reporters.

"The ambulance that went to Palenque in early January was because there was a risk of a heart attack and they took me to the hospital and recommended a catheterization," he said.

The government reported more than two weeks later that Lopez Obrador had undergone a cardiac catheterization procedure during a routine check-up on January 21 and was in "perfect health."

"In this procedure, the president's heart and arteries were found to be healthy and functioning properly," the interior ministry said.

"No other type of intervention was necessary and it was a brief procedure that lasted about 30 minutes," the statement added.

On January 10, Lopez Obrador announced that he had COVID-19 for a second time, saying he was experiencing mild symptoms and would isolate until he had recovered.

A week later he said that he had beaten the coronavirus for a second time, after a first bout a year earlier.