Northampton prop Mujati, 26, made the claims via his Twitter account on Saturday in the aftermath of Friday's friendly between the two clubs.
It is understood Heinke van der Merwe and lock Steven Sykes, the two players named by Mujati, denied the allegations. Mujati later deleted his postings.
In a statement released on Sunday night, the Irish club said: "Following the allegations made by a Northampton Saints player in the aftermath of Friday night's friendly between Leinster Rugby and Northampton Saints, Leinster Rugby acknowledge that there was an exchange during the match between two Leinster players which was misinterpreted.
"It was regrettable that any offence was caused. Both clubs have agreed that the matter is now closed and will now focus on preparing for their respective league campaigns."
Gilbert has released a new line of rugby cleats. The Gilbert Virtuo 8S is part of the exciting new product. Check it out.
The entire All Blacks apparel line has been updated for 2013/14. Check out the New Zealand All Blacks polo.
The Nike Tiempo is a solid rugby cleat and one of few styles still made from full-grain natural leather.
The Gilbert Blitz 8S rugby cleat is a great cleat at a great price of $69.99. Get a new pair of cleats today.
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Wear the crest of the British and Irish Lions on your t-shirt. A great look for the summer.
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The NEW All Blacks 2013/14 jersey has arrived at World Rugby Shop. Dare to wear the colors of the All Blacks.