It is thought some Leeds fans leaned over the hoardings at the side of the pitch and removed a microphone into the crowd.
An ITV spokesman said: "Unfortunately during the live broadcast of the FA Cup match one of the pitchside microphones was removed from its position by some fans and taken into the crowd where it picked up some swearing. The sound engineer immediately shut down all crowd sound and removed the affected microphone.
"We apologise to viewers for this incident which was out of our control."
He confirmed ITV would be addressing the issue with the club. And he said he was not aware of any viewer complaints.
Histon club secretary Lisa Baldwin said she did not know anything about the incident. She said she would speak to ITV and investigate what happened.