The witnesses, who sat on either side of Mr Prendeville as he exposed himself and masturbated under an in-flight magazine on board a flight on October 19, made the statements at Togher Garda Station in Cork yesterday.
Two members of the Aer Lingus cabin crew on the flight from London Heathrow to Cork have already made statements of complaint to gardaí.
The Garda investigation was launched on Wednesday after Aer Lingus lodged a formal complaint following the conclusion of its own investigation into the incident. Gardaí expect to interview at least three other people before speaking to Mr Prendeville.
They are also expected to examine why Aer Lingus took so long to make a complaint to gardaí.
Their investigation will take several weeks before a file is prepared and sent to the Director of Public Prosecutions.
In an emotional on-air apology on Wednesday morning, Mr Prendeville said he cannot remember anything about the flight, blaming a combination of alcohol and painkillers.
But he offered his deepest apologies to the airline staff, to passengers on the flight, to his family, his employers and his work colleagues.
Celebrity PR guru Max Clifford, who has been interviewed by the presenter of Cork’s 96FM’s flagship show several times, branded the apology “bizarre”.
“You don’t lose your memory, get it back, lose your memory, you would assume. That would give a lot of people cause to start asking questions.”
But Mr Prendeville’s friend, and legal advisor, solicitor Gerald Kean, hit back at Mr Clifford last night.
“He’s obviously receiving a different set of facts,” he said.
“Maybe he is trying to make a name for himself in this country at Neil’s expense.
“There is no in and out of memory loss here. Neil remembers everything to a certain point, and after that he just doesn’t remember.”
He defended Mr Prendeville’s apology as “sincere and emotional”.
“I genuinely believe he can’t remember anything. His apology is very clear. If he did something wrong, he apologises unreservedly.”
And he said at least two doctors have said people can suffer memory loss following the consumption of alcohol on its own.
Mr Kean said Mr Prendeville is “trying to cope with the situation” but has a “wonderful family and a wonderful set of friends”.