Invalid sim in Iphone4

[Bismarkab]

Hi, my brother brought me this iphone4 to me some weeks ago.
Unfortunately, when I place a Sim card in it, it always bring the message "Sim Failure" and then "invalid Sim".
Please, what can I do to do away with this problem?
Please help.

 

[das_stig]

The iPhone is locked to the original carrier, so you will need to get one of their SIMS, although this smells like a misappropriated item !