MADRID — A nationwide raid on a criminal group recently netted the Spanish police an extensive booty: 52 cars and motorbikes, as well as two boats, and 6.5 tons of gold and silver.

Rather than let the spoils go to waste, the Spanish interior minister and other top security officials lighted on a novel cost savings in these hard economic times. Four of the cars, it turned out, were newly armored and better than the ones they had. So they decided to use them.

Jorge Fernández Díaz, the interior minister, got special permission in April from a court in Valencia to use the armored cars for police purposes. The court is handling the investigation into the criminal group and overseeing its seized assets.

Confirming a report published this week in the newspaper El Mundo, Mr. Fernández Díaz stressed the cost savings of the unconventional vehicle upgrade. Four bulletproof cars used by the criminals are valued at about 400,000 euros, or nearly $540,000.