A court in Mexico on Monday formally charged four criminal justice workers for their alleged role in the July prison escape of drug kingpin Joaquin "El Chapo" Guzman.

A federal judge in the central state of Toluca said the four security workers failed to follow "protocols and norms" and did not notify higher-ups about the jailbreak in a timely way.

Two of the men charged were were prison employees tasked with video monitoring of El Chapo's cell. The other two worked for the Mexican intelligence service.

Three other workers were charged several weeks ago with aiding Guzman, 58, in his daring prison escape.

Guzman managed to flee the Altiplano maximum-security prison outside Mexico City, just 17 months following his capture after years on the run.

He slipped out of his cell through a 1.5-kilometer (one-mile) tunnel dug under his private shower in the prison some 90 kilometers west of Mexico City, and has vanished without a trace.

El Chapo's escape has dealt a heavy blow to the government of President Enrique Pena Nieto, which had pointed to Guzman's arrest last year as its biggest victory yet in its war on drugs.

The government has offered a $3.8 million reward for information leading to his capture.

It was the second time that that the drug lord has succeeded in escaping prison.

He busted out of another maximum security penitentiary in 2001.