IP address of Troll required

We have a troll on our forum who is an ex member who was deleted at their request. Now re-registered and masquerading as 'his mate' I suspect he has guessed or hacked a password of somebody and has been accessing their PM's.
Can I trace the IP address that a PM was opened from??

check in the members list and you will see all ip's the user has used.
if he hacked into your members account. then the ip will show up that he used.

Also if he has returned as a new member. then ban him this time. when ever you delete an account they can return.

as far as tracing the ip. if you have the ip you should be able to trace it.
Oh you might want to send the members account you think was hacked a email to tell him to change his pass. if he can not then you change it for him and email him back with the new pass. then tell him he can change it to what he wants

Thanks for getting back to me Kirk.
The guy who was hacked knows and has changed his p/w.
The guy who has reregistered has done so from his new office so the IP address is previously unknown. He hasn't posted as the other guy, just read his PM's.
I want to know if it possible to find the specific IP of the user that opened a PM. This will be the evidence I need to 'out' him.

I have reported it from the forum index page, should I have gone into the Sent item and then hit report to take you guys to the PM in question??

May I remind you that double/triple posting isn't tolerated unless separated by 24 hours (Use the edit button)

I am a bit unclear of the problem. However, its impossible to find the IP through a PM.

Apologies for the double post. Edit comment noted.
Member A has had someone go into his account somehow and read a PM as when he went into his Inbox it was already flagged as opened.
Whoever has done this has not posted whilst logged in as Member A, simply read the message, but people should not be using other peoples details to log in.
I want to know if we can find the IP address that the PM in question was opened from and if it matches the IP address of the guy I think is guilty.

As i said,

However, its impossible to find the IP through a PM.

Okay thanks anyway.