A source close to the family has confirmed an intermediary had written to both the Archbishop of Armagh Eamon Martin and Pope Francis in Rome seeking clarification as to whether Church law was complied with in allowing the wedding at St Fursey's Church, co Louth.
The source described the decision to allow McArdle to remarry on the same consecrated ground where Kelly-Ann rests as "hugely concerning".
It's understood the family are also seeking answers as to why the wedding took place in St Fursey's when the parish of Haggardstown and Blackrock also has a second church - St Oliver Plunkett's Church - which was not in use at the time of McArdle's wedding.
They have also asked for clarification on whether Canon Law dictates that a divorcee cannot remarry in a church, whereas a man convicted of killing his first wife can.
Sunday World this week attempted to put some of these questions to parish priest Fr. Padraig Keenan, who celebrated McArdle's wedding to long-term partner Claire Dollard in St. Fursey's Church in Haggardstown on Friday of last week.
We approached Fr Keenan this week as he exited St Oliver Plunkett's Church after a separate wedding.
After our reporter identified himself, he told Fr Keenan: "I wanted to ask you some questions about the wedding you celebrated involving Dermot McArdle in St Fursey's last Friday."
Fr Keenan replied: "No!"
The priest then continued walking towards his car.
Asked if he was aware letters concerning the wedding had been sent to Archbishop Martin and Pope Francis on behalf of Corcoran family, Fr Keenan made no response.
McArdle (53) served just two years in a Spanish prison after being convicted of the manslaughter on Kelly-Ann in Marbella on the first night of a family holiday together.
He was convicted of her manslaughter in 2008 after a Spanish court found her fall from the couple's fourth-floor balcony at the five-star Melia Don Pepe Hotel had occurred as the result of a row.
The jury of nine voted by a majority of seven to two to convict the then 39-year-old Dundalk father of causing the death of his wife Kelly-Ann Corcoran during a heated argument on the evening of February 11, 2000, the day the family arrived on holiday on the Costa del Sol.
The jury found that, as the argument escalated, McArdle pushed his wife on the balcony of their hotel room, causing her to fall over the rails.
In a very detailed statement, the jury foreman explained that on the basis of the evidence submitted, they believed that McArdle "did not set out deliberately to kill his wife" and therefore could not convict him of her murder.
However, it also rejected as "highly implausible" his version that Kelly-Ann tripped and fell to her death in trying to prevent their son from leaning over the rail.
The jury was satisfied that the reconstruction of the fall by police and forensic experts had showed that she could not have fallen over the rail on her own as alleged by the defence.
The jury foreman summarised the findings and explained that, based on the evidence, the jury was satisfied that "in the heat of an argument which turned violent" and which was heard by at least two witnesses, McArdle "pushed his wife on the balcony of their hotel room, causing her to fall over the rail".
Kelly-Ann died from her injuries two days later.
It was also alleged to the court that prior to Kelly-Ann's death McArdle had been abusive towards his wife - but this was denied by McArdle's sister.
McArdle claimed his wife fell in a freak accident.
But Roy Haines, an Englishman staying in the room next door, remembered things differently. He told the court that prior to Kelly-Ann fatal fall he heard a commotion that sounded like arguing.
He said he went out onto his balcony and saw a man holding a woman "above his head".
"I told him to put her down," he told the court,
"I went inside and shut the door."
Soon after, he said, he heard cries for help.
"There was nothing we could do. She was down."
The court heard as an infant McArdle's son had told a relative his dad had "pushed" his mum.
Kelly-Ann's brother-in-law, Peter Moran, gave evidence that then three-year-old Mark told him on his return to Dundalk: "Daddy bold, Daddy pushed Mammy."
McArdle had claimed Kelly-Ann saw her son on the balcony and went to grab him before tripping and falling over the railing.
He said he grabbed her arm but was unable to hold her and said in his evidence "We are Catholics and we would not lie."
But the jury found against him -an acknowledgment that Catholics are every bit as capable of lying to save their skins as anyone else.