The father-of-six, who lived in London with his family, was pronounced dead at the Camber Sands holiday park in Lydd Road
Father-of-six Michael McDonagh (53), who lived in London with his family, was pronounced dead at the Camber Sands holiday park in Lydd Road near the East Sussex border last month following an altercation between a group of people.
Seven people who had have arrested on suspicion of murder after McDonagh died at the Lydd Road site shortly after midnight on Saturday, August 6, have been released under investigation while enquiries continue.
An appeal for witnesses was launched, but detectives say they are particularly keen to speak to people who may have recorded the incident on mobile devices.
“At least one man, described as short and thin by witnesses, is believed to have recorded the incident from start to finish,” Sussex Police said in a statement.
“We would encourage this person to come forward or if anybody knows who this person is to make contact with the investigation team.”
Anybody with footage, images or information that could help with the investigation is asked to contact police online or via 101, quoting Operation Molton.
In the wake of her father’s death one of McDonagh’s daughters, Stephanie McDonagh, said she wanted justice for her father and to make sure it was "an incident that will never be repeated again".
Mr McDonagh's other daughter, Shannon, said: "This is just extremely shocking that in a park resort where you expect - you know there's families, there's children - you don't expect something like this to happen, you expect it to be safe."
McDonagh is believed to have got into the row after watching the opening match of the Premier League between Crystal Palace and Arsenal.
It has been reported that he was held down by a number of men and had stated he couldn’t breathe.
In 2000, the Criminal Assets Bureau successfully seized McDonagh’s home near Ballintogher, Sligo after proving that it was bought from the proceeds of crime before the courts.
Soon after that Mr McDonagh left Ireland, he returned and he stayed in local hotels with his family.
He was also on the radar of the National Crime Agency in Britain and was arrested in Amsterdam, Holland in November 2010 and extradited back to the UK on foot of an international warrant for his arrest.
He was subsequently jailed for seven years for drug trafficking.
The family of the Sligo dad had earlier said they were “walking away with broken hearts and unanswered questions”.
He was described as a man who was the “centre of our world and the life and soul of every party”.
“On Saturday morning we found out we lost our father,” a family member said. “Michael was a loving and supportive husband of 32 years and a father of six, taken from us whilst on a family holiday.
“His family meant everything to him. He came away to make memories with his wife and children and instead we are walking away with broken hearts and unanswered questions.
“It’s impossible to put into words how we all feel. Our dad was the centre of our world and the life and soul of every party.
“Not only did my dad make such a huge impact on our family but also to countless people who knew him throughout his life. He will be greatly missed.
“Michael was a kind-hearted man who died too young, leaving behind all those that loved him.”
Sussex Police described the attack as an "isolated incident", saying the investigation was "complex and fast moving".
A spokesperson for Camber Sands holiday park, said: "The safety and wellbeing of everybody on our park is at the heart of everything we do.
"The police have issued a statement providing reassurance to the public that this was an isolated incident with no wider risk of harm.
"As this is a live police investigation we cannot comment further, but our park team is actively supporting the police and is doing everything they can to assist with their enquiries."