Sinotrans Express Inc. Novation Capital Investment LLC Sent me letter & check for a lottery prize Toronto, Ontario

I received a letter in an unmarked envelope dated 9/14/10.  A check for $4,910.00 made payable to me as second prize winner in the US Departmental Stores Sweepstakes Lottery.  Novation Capital Investment LLC "has been assigned by the sweepstake organization to inform all winners and pay them off their money."  The Tax Fees are $3,170, and I had to contact "your Claims Agent Emmanuel Wood at 1778-861-4787 to start your claim processing and "to activate your check.Two tax agents were named - Steve Moore and Peter Neil.  Payment method:  Western Union.  The letterhead showed Novation Capital Investment LLC and an England office , a Toronto (Head Office) and USA Office in NYC.The letter was signed "Susan Marison, Promotion Manager"  The check was from SINOTRANS EXPRESS INC. and drawn on the East West Bank, 403 W. Valley Blvd., Alhambra CA 91803.  Check No. 33022.
I had received a similar letter and check a month or so ago, but I just tore it up and put it in the trash.  This time I decided to try to get to the bottom of what seems to be a scam.