New video in Mexico reveals hammering sounds several minutes before the country's most notorious drug lord escaped from his cell through a tunnel.

The closed circuit prison video broadcast Wednesday by Televisa shows a longer segment of surveillance on Joaquin "El Chapo" Guzman on July 11 than what the government released. It also includes sound.

Guzman can be seen lying on his bed under a blanket watching television when the hammering begins. A split screen with the prison control room shows no one reacting.

Even when Guzman disappears into the tunnel in the floor of his cell's shower, there is no visible reaction in the control room. Twenty-five minutes pass before two officers gather in front of screens and talk.

Almost 30 minutes pass before guards appear outside the cell.