Some points to raise with your management and sorry for you.
>I'm not sure ethically
Better be sure legally.
1. Is the risk worth company reputation ?
2. The client is buying 'company' if nothing else there, client will be 'frustrated' for cheating them. How hard is to build new relations ? Does it cost more than the profit from the project ?
3. The 'company' is at mercy of vendor for not showcasing the work done.