Ulster Rugby have apologised after a picture showing some of its players wearing black make-up was posted online - with Ireland international Paddy Jackson dressed in what has been described as a 'slave' costume.
The image - which was posted to Paddy Jackson's Twitter account - shows fellow Ulster player Chris Henry and three others, wearing black make-up on their faces, waving an Ethiopian flag.
It has since been taken down from social media.
In response, Ulster Rugby said they apologised "unreservedly for any offence".
The club said the photograph had been taken from an "Olympic-themed fancy dress party" which was held two years ago.
"It was not the intention of the players to cause upset and the photograph has since been removed," the club said.
Fly-half Paddy Jackson is dressed in what has been described as "an outfit depicting slavery".
The photograph has been blasted by Joseph Ricketts of the African and Caribbean Support Organisation Northern Ireland.
He said he was "shocked and appalled" after he was first shown the image by the BBC.
"I was shocked, and especially shocked by the man wearing something that looked like a chain around his neck," he told the Belfast Telegraph.
"That alone escalated the whole thing.
"It mimics the worst period for black people - slavery."
He said the message the photograph was sending out was "extremely dangerous" as the rugby stars are "icons that young people look up to".
"It is not good for young people here," he said.
"People are just appalled by this. Some others may think this is just having a bit of craic, but many people are deeply offended it.
"When we have prominent figures and sporting stars, on social media doing things like this, it filters down into the community."