Run Athletics president, Rasheed Young, had his lawyer send a letter to the brothers last fall, accusing them of hiding the money, which he is potentially owed.
Russell Simmons' and Reverend Run's business partner has declared war on the hip hop moguls -- claiming they've hijacked MILLIONS in profits from their kids shoe company ... and now, he's gearing up to sue.
Lawyers for Rasheed Young -- President of Run Athletics -- sent Russell and Rev. Run a letter back in November, accusing the brothers of secretly funneling millions in revenue from their Pastry brand of footwear ... into a company that Rasheed isn't a part of.
Rasheed claims Pastry has raked in tens of millions in sales -- and so far, he hasn't seen a penny of it.
Wallace was reportedly left with no choice but to take further action after his letter was met with no response. He has promised to sue if the duo doesn't pay up.
Provided that his story is factual, Young stands to get millions, as Run Athletics Pastry shoe line has been very successful. Back in 2007 the line, started by Rev Run's daughters, Vanessa and Angela, had $15 million in profits for the year. The line is estimated to be worth $50 million today.