What a quick responce:

ATTN SIR
WHY CAN'T YOU GIVE THEM OUR PHONE AND FULL ADDRESS SO THAT THEY CAN CONTACT US AND ASK ABOUT THE CHEQUE?
NOW WHAT IS YOUR MIND TORWARDS IT? CAN I RETURN THE CHEQUE BACK OR WHAT?.
EARLIER THE BETTER
YOURS FAITHFULLY

So I think we can safely say that this gentleman is not worried about being investigated.

Me thinks I should let him stew for a few days.... I am sure I could make up the fact I was arrested (again)

Boy this guy really is falling hook, line and sinker:

ATTN SIR.

OPEN YOUR ATTACH AND SEE COPY OF YOUR CHEQUE . YOUR CASHIER'S CHEQUE IS USA DOLLARS NOT CANADIANS DOLLARS.
EARLIER YOU SEND FEDEX EXPRESS CHARGE FAST YOU RECIEVE YOUR CHEQUE.

EARLIER THE BETTER
YOURS FAITHFULLY
CHIKE PAUL

This really is too good to pass up the opportunity to wind the bloke up a little more:

Good Morning Sir,

Thank you for your swift reply. I did see my copy of the "cheque" which you so gladly sent to me. I was about to enter a Western Union branch to deposit your money when I had an interesting phone call from my secretary. It appears that our business dealings have arroused problems with the Fraud Unit of the Metropolitan Police here in London. I was arrested on suspicion of embezalling monies in a number of "projects" in the US and Europe and wanted to know who my contacts were. Obviously with our arrangement being legal I passed on the emails from yourself and Mr Barry and directed them to your phone number in order that they can clarify your end of the bargain.

Obviously they have let me go while they check out the story with you, however I have had to hand over my bank accounts and company credit facilities to the Police while their specialist teams conduct their investigations.

I hope you can understand the delay.

William