Vicky Kloss, City's director of communications, was attempting to make contact with manager Roberto Mancini ahead of his TV interviews before the FA Cup tie when she was told by a steward she would not be allowed into the players' tunnel.
City claimed she was told she was being denied entry because she is a woman, which Notts County deny. More angry words were exchanged after the 1-1 draw.
Notts County denied the claims from City, insisting Kloss was not prevented from entering the area because of her gender, but because she did not have the right pass.
A County spokesman said: "It's nothing to do with her being a woman. She was trying to get into an area without the correct accreditation."