Police clearance certificate for UK

Dear all,
Thanks to this forum, I was able to learn alot of the visa hassles.

I have a further question now, that I'm presently in India and would be taking up a job offer in UK shortly. My employer has asked me to get police clearance certificate.
On further searching the web, I got the information that we can obtain it from District Police station(City Commissioner's Office) and also from Passport Office. (essentially passport office inturn forwards the application to district police station and get it back from there.

I applied at City Commissioner's Office for one reason that they donot ask to submit original passport, unlike passport office.

[b]Does anyone have previous experience regarding this? [/b][b]Is it as acceptable as the Passport Office clearance certificate for a job in UK?[/b]