How to stop a nomination

[angelbrat]

My company is currently sponsoring someone under the BCPNP. She effectively has not fulfilled her side of the contract and we wish to withdraw our sponsorship. We know her PR file has been transferred to Seattle from Buffalo, where she may or may not have to go for an interview.

Do we just call BCPNP and tell them we no longer want to sponsor her and then let immigration decide what to do or do we have to inform immigration ourselves.