The former head of Mexico's federal prisons and the ex-director of the Altiplano penitentiary that drug lord Joaquin "El Chapo" Guzman escaped from are among 13 recently arrested people, an official with the federal prosecutor's office has said.
A statement from the prosecutor's office on Friday said 11 men and 2 women had been arrested, but did not name them.
Celina Oseguera Parra, who oversaw the country's federal prisons, and Valentin Cardenas Lerma, the Altiplano prison director, were among those arrested, said an official with the prosecutor's office told the AP news agency. The official spoke on condition of anonymity because they were not authorised to be quoted by the press.
Oseguera Parra and Cardenas Lerma were both forced to resign after the July 11 escape.
The suspects in the latest batch of arrests also included Leonor Garcia Garcia, head of the prison's legal department and top official on duty the night of the July 11 prison break, the official said. The other 10 suspects also worked in the penal system.
A federal judge this month began proceedings in the case against four officials, including two intelligence service members and two prison control room employees. They were accused of aiding Guzman's escape through a tunnel dug to his cell.
Proceedings were already under way against the person in charge of the penitentiary's control room and two prison guards.
Guzman, head of the Juarez Cartel, also escaped from another maximum security prison in 2001.