Willie Frazer has strongly denied posting a tweet criticising the DUP for putting up green and white balloons outside a party office - during a cancer fundraising event.
The message was posted along with a photograph yesterday morning, around the same time Mr Frazer was appearing at Belfast Magistrates Court on charges connected to flag protests.
Several green and white MacMillan Cancer Support balloons were stuck to the front of DUP assembly member Jimmy Spratt's Cregagh Road constituency office in east Belfast during a coffee morning yesterday in aid of the charity.
Both Mr Spratt and Mr Frazer have experience of cancer.
A short time later the offensive tweet reading: "DUP showing their true colours... A vote for the traitors. A vote for terrorists in our government. Get them out!" appeared with a picture of the office on an account claiming to belong to Willie Frazer.
The victims' campaigner - who previously confused an italian flag flying outside a Catholic school for the irish tricolour - last night insisted he does not have a Twitter account and vowed to have the fake tweets removed from the internet. "When [Jimmy Spratt] is doing something like that you don't stoop that low," he said. "i would not condone that and i have no love for Jimmy Spratt but i would not be saying things like that. "Somebody must be using my name. it's definitely not me. i don't know how to use Twitter."
Mr Frazer spoke of his own illness. "i have cancer myself and i would hardly be running him down for running something for cancer when i have something similar myself," he said. "Whoever is at it knows me and Jimmy Spratt don't get on."
A spokesman for the DUP last night called on whoever was responsible for the post to "delete the tweet and account" as it was "embarrassing to Willie and offensive to everybody".
Never far from the headlines, Mr Frazer was previously forced to issue an apology after he branded a Catholic primary school in Co Tyrone "the junior headquarters of SF/iRA youth". it emerged he had mistaken an italian tricolour being flown at St Patrick's Primary School in Donaghmore in May last year for an irish tricolour.