immigration and the NHS

hello everybody.
this may sound like a banal question, but i would like to know if the NHS can report illegal immigrants to the UKBA.
if yes, what about confidentiality and data protection act?

thanks!

They can share information with other government departments about a crime. Overstaying, illegal entry and using forged documents are all crimes. Hospitals have overseas visitors liason people to get payments from patients who have no entitlement to free NHS non-emergency treatment, and no doubt they work with UKBA.