Undetectable Alignment

Player's Handbook v.3.5 (PH)Core (3.5)

School: Abjuration
Casting Time: 1 standard action
Components: V, S
Range: Close (25 ft. + 5 ft./2 levels)
Target: One creature or object
Duration: 1 day
Saving Throw: Will negates (object)
Spell Resistance: Yes (object)

An undetectable alignment spell conceals the alignment of an object or a creature from all forms of divination.