Hijack TM Phone Line

TM = Telekom Malaysia.

Some time ago, I received a fowarded message about the method to "hack" into someone else TM account. The message goes like this..

Urgent Message from TELEKOM

To those who have a telekom home phone, please read. Here is the original text received from Telekom:
If you get a call from someone identifying himself as a phone
technician performing a test, and this person asks you to touch nine(9), zero(0),hash sign (#) and then hang up... Please REFUSE TO DO SO!
By pushing 90#, you are giving the individual, who called you, access to your telephone line and allowing them to place a long distance call with the charges appearing on your telephone bill.

We were further informed that line scam has been originating from many of the local jails/prisons.
Please pass the word around.

Can anyone verify this ?