Jay-Z and his partners are being sued for $7 million

Clothing designer Dwayne Walker claims in a lawsuit that he is owed money by the `99 Problems` hitmaker and his former Roc-A-Fella record label in unpaid royalties after designing their logo, which features a letter "R" over a vinyl disc and a champagne bottle.

The documents - which were filed in Manhattan Federal Court, New York, on 12.07.12 - state: "The logo has become universally recognised as an iconic symbol of Jay-Z, one of the most successful recording artists in the history of popular music."

Dwayne claims to have devised the logo in 1995, when Jay and his former business partners Damon Dash and Kareem `Biggs` Burke founded the record company, which is now a subsidiary of the Universal Music Group.

Last month, the 42-year-old rapper - who is married to singer Beyonce Knowles - was sued for plagiarism by author Patrick White, who alleges Jay stole portions of his writing and then used them for his own memoir, `Decoded`.

In the lawsuit, Patrick claims: "In 2009, my personal computer was compromised, resulting in my personal work to be used in Jay-Z`s book `Decoded` which was released in 2010.

"The book contains various expressions/colors/phrases which correlates to my work. After contacting or attempting to contact the co-author, I got no reply."

sections: Celebrities