MADRID, Spain (AP) _ Spanish police officers settling in for a video presentation on how to get promoted to sergeant were instead shown footage from a hard-core pornographic film, officials said Tuesday.

Howling laughter rippled through the auditorium where 120 Madrid city police officers had gathered Monday to see the video on operations at an academy where they are to study, the Madrid regional justice and interior ministry said.

A ministry official said computer technicians have blamed the glitch on a Trojan Horse computer virus that activated when the computer containing the video was turned on.

``It was just bad luck that the virus activated right then,'' said the official, who could not be named because of department rules.

The person operating the computer stopped the video and turned it back on several times but each time the porno movie came back on, so the operator eventually just shut the computer off altogether, the official said.