A prison director is being investigated after she was pictured twerking in front of hundreds of sex-starved inmates at a jail in Colombia.

Claudia Patricia Giraldo Ossa - head of the prison in Cali - was snapped in a series of pictures dancing erotically inside the jail at a prisoners' cultural event.

Ossa, wearing a shoulder-revealing halter neck top, skinny jeans and stilletos, jumped up on the stage and even danced alongside some of the prisoners.

Meanwhile other inmates that packed out the courtyard at Villahermosa jail cheered her on without a single prison guard in sight.

Colleagues say Ossa had not intended to perform at the event but had got carried away when inmates called for her to get up on a makeshift stage.

Officials say she now faces a disciplinary inquiry at her jail.

Local media reports she has not commented on the scandal.

The scandal emerged as Colombia's new Minister of justice, Jorge Londono, declared a state of emergency in the country's prisons.

Overcrowding is said to be causing severe problems with drug abuse and violence with most jails struggling with occupancy levels of more than 150 per cent.