FORT COLLINS, Colo. (AP) _ Seventeen people who received letters telling them they had won a free dinner and lottery tickets were arrested on outstanding warrants when they showed up to claim their prize.

''They were shocked, they were stunned,'' said Michael Goodwin, of the Fort Collins Police Department's selective enforcement unit. ''They weren't believing it because this looked so real.''

The 17 were among 575 people wanted on outstanding warrants. The letters said the recipients had won a dinner for two at a fictional restaurant and 50 lottery tickets.

The ''winners'' were told to collect their prizes Saturday at the Western Marketing Research office. When they arrived, they were greeted by a secretary who said the letters had to be verified.

''When the warrant was verified I said, 'Good, we're in business. Come on back, we've got a couple of papers to sign and we'll have you out of here in a couple of minutes,' which was the truth,'' said police officer Terry Seal.

Ten were arrested on outstanding felony warrants and the rest were arrested on misdemeanor warrants.