How to trace a private IP Address location?

[ecapsnet]

Hi,
I have a query regarding, please help me if somebody knows how to trace the location of a private ip address.

One of my friend is getting threat from unknown person; the incoming email id is is ******@gmail.com which is using private ip address.

Please help me to trace the location of the person.

Thanks for your response.

Regards

[Manov]

If you have the IP address, and need to find out who is the registered owner of the address, try
Query the APNIC Who is Database (http://wq.apnic.net/apnic-bin/whois.pl/)

[josephvijay]

You cannot do anything with an IP address. All you can do is find the basic geographical location and the ISP details of the IP address through any IP lookup sites like IP-Details.com (http://www.ip-details.com/) . If you are really facing any problem from the IP address, better make a complain to the police.

[astuartspindlow]

There are lots of IP address checker available of free.