The photos and video were later posted on a social media site.
The offending images were all removed within 24 hours of being posted.
Gardai are now investigating all circumstances of the incident which is alleged to have occurred in the south Cork area.
However, no formal complaint has yet been made.
The 15-year-old boy was singled out by a group of youths last week.
Karen O’Mahony of the Cork-based Masquerade Ball support group for special needs children, said people are in disbelief over the appalling incident.
The family of the boy involved do not want to be identified though they are said to be “totally distraught” by what happened.
They only discovered what had happened when a youngster who lives nearby called to their door to alert them.
“It was very, very distressing. In fact, I am still upset simply by the details of what happened,” Karen said.
“This was a terrible thing for any child to be subjected to let alone a young boy with special needs.”
An appeal for information on Cork radio station, 96FM, generated an overwhelming response.
It is now believed that a total of five youths, aged between 14 and 16 years, were involved.