The L.A. County Sheriff's Department feels "used and manipulated" by Michael Jackson's family members who reported Katherine Jackson missing ... this according to Sheriff's Dept. sources.
Members of the Dept. familiar with the situation tell TMZ ... they believe MJ's family members knew Katherine was not in danger but used the Sheriff's Dept. as a "pawn in the middle of a family game."
Sheriff's sources grouse that their budget has been severely cut which makes bogus claims sting even more than usual. They believe the end game here is money.
As you know ... MJ's brothers and sisters want Michael's will invalidated so they can get a piece of the pie. But there's a BIG problem. If the will is invalidated, the prior will gets resurrected, and under that document Michael's siblings are completely cut out.
Sheriff's spokesperson Steve Whitmore tells TMZ, "We don't feel manipulated. We respond professionally to all such reports."
BTW ... no matter what the family's motives, the Sheriff's Dept. will continue to investigate the claims.