This all sounds a bit dodgy to me. Being a good citizen, I called the police immediately, so they took my PC away to look into it further.
You have been lied to. Either:
a) the police have had nothing to do with this petty tail
b) someone has done a lot more than hack an email account (child images or terrorism etc) and the police have taken the PC
You have been lied to. Either:
a) the police have had nothing to do with this petty tail
b) someone has done a lot more than hack an email account (child images or terrorism etc) and the police have taken the PC