Marie Curie Cancer Care is considering what action to take after a flyer for an event being held in memory of a dead IRA bomber said it was raising money for the charity.
The tug-of-war event is due to take place on Saturday in the village of Pomeroy, County Tyrone.
It is being held in memory of Seamus Woods, an IRA member who died while trying to launch a bomb attack in 1988.
A spokeswoman for Marie Curie said it was unaware of the event until it was contacted this week.
"We were not aware of this event, have no involvement and were unaware that our logo was being used to promote the event," she said.
"Members of the public often create their own events to benefit Marie Curie or decide to donate proceeds from an existing event without advising us."
Asked whether the charity would accept a donation from money raised at the event, the spokeswoman said this was "still being reviewed".
Joel Johnston, party secretary of Traditional Unionist Voice, which opposes power-sharing, said a member of the public had contacted it to complain about the use of the Marie Curie logo on the event’s flyers.
Jim Allister, the TUV leader, said the charity "should not be abused by this event in an attempt to bring a veneer of respectability to a celebration of terror".
Third Sector attempted to contact the club secretary at Pomeroy Plunketts, which TUV said was organising the event, but did not receive a response.