It's been a tough 2014 for Sean Kingston. Just this year alone he had a Mercedes-Benz G-Class and a Lamborghini repossessed, and he was accused of having a club promoter beaten up.

Now the singer is being sued by Avi Da Jeweler for owing money on necklaces, watches and expensive diamond pendants.

According to the jeweler, Kingston failed to pay him between the years of 2008-2013, yet he kept all of the jewelry anyway. He's also accused of writing several checks to Avi, which bounced.

But a rep for the 24-year-old told TMZ the claims are untrue. "Mr. Kingston has paid Avi Da Jeweler well over $300,000 for jewelry that was appraised at far less than that and has the cashed checks to prove it," said the representative.

"Additionally, no one would continue to supply jewelry to another individual for five years without ever receiving payment. Mr. Kingston fully intends to fight his lawsuit in a court of law."

There's been no word from Kingston yet on the accusations.