BUENOS AIRES, Argentina (AFP) - Argentine train drivers have been caught on video half asleep at the controls, talking on cell phones and reading books since a deadly rail crash in June, officials said on Wednesday.

"Less than a month after cameras were installed in train conductors' cabs, the results have been overwhelming," said Transport Minister Florencio Randazzo.

Mr Randazzo showed video images taken from the surveillance cameras which showed drivers nodding off, on the phone or reading, sometimes with their hands off the controls altogether.

A driver seen struggling to keep his eyes open "has already been relieved of his duties," Mr Randazzo said. "He was driving a train with a thousand passengers." His disclosure came as investigators in Spain found that the driver of a speeding train that derailed in Santiago de Compostela, killing 79 people, was talking on a cellphone at the time.

Argentina began putting surveillance cameras in conductors cabs after three people were killed in June when a passenger train slammed into another train at a station in the western outskirts of Buenos Aires.

In February 2012, 51 people were killed and more than 700 injured when a train slammed into a retaining wall in a station in Buenos Aires.