Organisers of Michael Stone's art exhibition say they regret the hurt caused to the family of the late Dermot Hackett by hosting the event for the loyalist killer.
The exhibition was held inside east Belfast community project Reach UK, which was set up by former members of the Red Hand Commando paramilitary group.
The group says it supports initiatives from all sections of the community and was invited to consider hosting a free one-week exhibition of artworks from Stone's Milestones collection.
Robin Stewart from the Reach Project was pictured standing beside Stone at the exhibition launch last month. He said the organisation volunteered space to host the 25 art pieces and a free-to-attend opening evening in mid-July.
"The nature of the request was to display some of Michael's artwork and at the same time publicise the Prison Arts Foundation," he said.
"We discussed the possibility that this exhibition might be controversial but Michael wanted it to be a low key event."
Mr Stewart added: "We regret the hurt and pain caused. Michael also recognises the hurt that his past actions have caused and he understands how that can have an impact on the victims' families.
"He is an artist who is in prison but who will shortly be released. All prisoners, whether unionist or nationalist, have limited options about how they will reintegrate into society and art is Michael's preparation for that. He is showing other prisoners that there is hope for them when they come to be released and rehabilitated so they don't re-offend."
Since news of Stone's display of artwork came to light, Mr Stewart says there has been a surge of interest in the exhibition.
"We sold a number of paintings at the launch and have had more emails today from people locally and across the UK looking to come and view the works with an interest in buying. Some of these may be people genuinely interested in the art or because of who the artist is."