The offending segment with Eadie, pictured left, was not intended to air, but was broadcast after an editing mix-up.
The clip, which was removed from any repeat showing on the channel or online by Archant, can still be seen on YouTube.
In it, Helen said: “This is what happened when this c*** went to Happisburgh beach to look at some fossils or something.”
Helen, a former Anglia Television newsreader, has since publicly apologised on the channel for the language used in the take.
The gaffe comes after another local TV channel, Made in Leeds, was rapped by regulator Ofcom earlier this month after the same word was used by a member of the public in a vox pop during its very first broadcast.
The foul language was then aired again during a repeat broadcast of the show the following morning.
Fiona Ryder, managing director of Mustard TV Ltd, said: “In a recent pre-recorded segment of a Mustard TV show, presenter Helen McDermott used inappropriate language in an exchange with a colleague.
“The segment was subsequently re-recorded, but the wrong edit of the segment was broadcast. Helen and Mustard TV apologise for this lapse and for any offence caused.
“An apology from Helen was carried on Mustard TV at the next available opportunity and the inappropriate language was removed immediately from any repeat showing live or online.
“Internal disciplinary action has been taken with the presenter concerned.”
Ofcom says it has not received any complaints about the incident.