letter stating I won a shoppers sweepstake lottery with what appears to be an official check

received letter stating I won shoppers sweepstakes $125,000 a ck. for $3875.oo was with letter sent from Imperial Financial Links Inc. issuing co. name Moore & Van Allen,pllc Attorneys at law.I investigated and found ck.#442280 was issued to Jeffrey Glenney (aka claims/disbursement agent Mr. Jeff Nelson?)and cashed by Jeffrey on Nov.20,2009 for a lesser amount. Spoke with Mr. Jeff Nelson and He is now accusing me of trying to cash ck.#442280 twice. He said I should send $2875.00 thru western union to Christina Cunningham in New York city, at 270 Broadway and would not give a ph.#.SCAM SCAM

ck#442153 came with my winning notification. I'm not even going to bother...

My mother has also been a victim of this fraudulent scam.  She also has cashed the check earlier this week before the holidays but have not received any harrassing phone calls yet.  Any advice?