MEXICO CITY (AFP) - The Mexican authorities have arrested 13 more people over the escape of drug kingpin Joaquin "El Chapo" Guzman, including the former head of federal prisons and the former director of his penitentiary.

Ms Celina Oseguera, the former national coordinator of the federal prison system, was among those detained over Guzman's July jailbreak, an official in the attorney general's office told AFP.

The authorities also arrested the former director of El Altiplano maximum security prison Valentin Cardenas Lema, and the facility's legal director Leonor Garcia, the official said on Saturday.

The 10 other suspects were guards and personnel at El Altiplano, where they will now be held, along with Mr Cardenas.

Ms Oseguera and Ms Garcia are being held at the female prison in Tepic, in the western state of Nayarit.

The Mexican government sacked Ms Oseguera and Mr Cardenas days after Guzman - head of the Sinaloa drug cartel - escaped on July 11.

A total of 20 officials have now been arrested in connection with the escape.

Mexican investigators say that Guzman, Mexico's most powerful drug lord, had key inside information to ease his escape, as well as support or acquiescence from prison insiders.

Guzman's escape, in which he crawled through a hole leading to a huge tunnel under his cell shower, was a major embarrassment to President Enrique Pena Nieto's administration.

He had been in prison for just 17 months.

Guzman had broken out of another Mexican prison in 2001 and was caught 13 years later in Mazatlan, a tourist resort on the Pacific coast.

A US$3.8 million (S$5.3 million) reward is being offered for Guzman's arrest.