Loop invariants play a major role in program verification. Though various techniques have been applied to automatic loop invariants generation, most interesting ones often generate only candidate invariants. Thus, a key issue to take advantage of these invariants in a verification process is to check that these candidate loop invariants are actual invariants. This paper introduces a new technique based on constraint programming for automatic verification of inductive loop invariants. This approach is efficient to detect spurious invariants and is also able to verify valid invariants under boundedness restrictions. First experiments on classical benchmarks are very promising.