Secondly, if the account is freezed for investigation by the police, then the chance is very little that you will get back your account ever in your life! So if the amount is small, it's better to forget about it. Otherwise, hire a lawyer and file a court case as well as involve consumer protection forum into that. That's the only way you will get back your account.
He will get his account back, once they froze the account because of illegal activities they will ask you to present yourself for questioning and if you could give them the proper answer and provide the proof of transaction which the OP can very well submit the details from his local bitcoin account and then you will not get into trouble, but he will not get the amount credited through hacked account.