The Garda watchdog has said that it may investigate a video which appears to depict a garda pinning a homeless man to the ground with his foot and using pepper spray on him.
A spokesperson for the Garda Síochána Ombudsman Commission last night said it was examining the video to decide whether or not they will carry out an investigation into the incident, which occurred in Dublin last Friday.
The recording, which was filmed on Dublin's Henry Street, has sparked outcry and accusations of disproportionate force from the garda.
A garda superintendent, from outside the district, has been appointed to conduct an internal inquiry into the incident, which was caught on film by DIT student Philip Campion.
The minute-long recording appears to show the male garda using pepper spray on the homeless man, who was lying on the ground, while arresting him.
Security sources have said that the man was refusing to cooperate with the gardaí after being approached by them.
"He was asked to move, but he didn't. He grabbed the garda's pepper spray, but the garda grabbed it back and used it on the man," a source said.
"The garda did use his foot but he applied minimal force as he waited for backup," they added.
The source then alleges that the homeless man, who is a Polish national, went on to try to assault the garda and was subsequently arrested.
Some of the capital's leading homelessness campaigners have described their shock at the footage and are calling for an investigation into the incident, with Fr Peter McVerry describing it as "absolutely shocking".
Lord Mayor of Dublin Christy Burke, who is heavily involved with the Inner City Helping Homeless organisation, is now calling on Garda Commissioner Noirín O'Sullivan to oversee an investigation into the circumstances surrounding the incident.
"I want to see an investigation in relation to the whole incident," Mr Burke said last night.
"It removes as far as the incident is concerned, any dignity that Garda senior management said that gardaí would have for homelessness. Because that doesn't show anybody with dignity and integrity in their approach to a homeless man or woman," Mr Burke added.
"He was powerless. The individual was powerless lying on the ground. The garda had his foot on him at one stage and then the pepper spray," he said.
Mr Burke said that the incident was "totally unacceptable and absolutely appalling".
Philip Campion uploaded the video to his Facebook page and it has been viewed more than 500,000 times since.
He described how he observed the incident on his way from college and branded it as "absolutely outrageous behaviour" by a garda on one of the busiest shopping streets in the country's capital.
The 20-year-old said a crowd of around 20 or 30 people gathered and some had called on the garda to stop what he was doing, but he urged them to go away for their own safety.
It is reported that the investigation will seek to determine if the pepper spray was used before or after the man was placed in handcuffs and if and why the garda decided to place his foot on the individual.
Fr McVerry last night said that he "certainly very welcomes" that an investigation will be held and that it raises questions about society's attitudes into homelessness.