The issue isn't with the search. The search was concluded at the time the evidence was seized. The issue is with the seizure method.

Can evidence be suppressed if it was discovered via a lawful search but unreasonable force was used in it's seizure?

It is my understanding that the evidence stands as it is not the "fruit of a poisonous tree," but the officer may be civilly or criminally liable if he/she is not entitled to qualified immunity.