N’Diaye joined Sunderland in January in a £3m deal from Turkish side Bursaspor.
the incident with the car happened around 8pm on Monday when his brother was behind the wheel of his luxury Bentley Continental near to the Hilton Hotel in Gateshead.
N’Diaye was seen with his head in his hands as he was told his white convertible was going to be towed away after concerns involving insurance arose.
A hotel guest watched events unfold: “I was walking past the Hilton on the road that runs outside it and there was a police Land Rover with its lights on parked up blocking in a white convertible Bentley.
“They always stand out immediately and I thought, ‘hold on a minute this has got to be a footballer getting pulled over’.
“Two young guys were sat in the back of the Bentley having a good old chat with the copper and one of them was sat there with his head in his hands looking like it was really bad news.
“He got out of the car and the cop was giving him a bit of paper and they just walked away from the car. I went up to him and said ‘are they taking your car’ and he said yes.
“I asked what the problem was and he said it was something to do with insurance. “I’m not a massive football fan but I noticed the guy’s French accent when I spoke to him and the French number plates so I asked him his name and he said Alfred.
“When they finally walked away from the car, him and his mate walked straight back into the Hilton hotel so I’m guessing they might be staying there.”
A police spokesman confirmed a Bentley was towed by officers on Monday evening.