Sunday World can reveal that gardaí are investigating whether the north inner city based man sent a photo of Mr Flynn’s grave to the alleged victim which was accompanied by text which could be deemed to be threatening.
The incident happened over the Christmas period and the alleged victim made a complaint and statement to gardai after receiving the communication.
“Gardai haven taken a cautioned statement from this individual who is aged in his 60s,” a source said.
“This man’s actions could be considered to be an attempt to interfere with due process or be an attempt to pervert the course of justice.”
Gardaí visited the home of the suspect last night.
Detectives are continuing to investigate the sexual assault allegations against Mr Flynn who was aged 34 when he died by suspected suicide at his East Wall home last August.
After allegations of sexual assault emerged against Inner City Helping Homeless (ICHH) founder and CEO he was suspended by the company.
The Dublin city councillor had been under investigation by gardaí in relation to two alleged sexual assaults. Subsequently, another two men claimed they were also sexually assaulted by him.
One of the two men who made the original complaints to gardaí is described as an "extremely vulnerable" 21-year-old male who said he took a taxi, paid for on the charity's account, to Mr Flynn's home before he was drugged and sexually assaulted last May.
The alleged victim woke up the following day and later went to a Sexual Assault Treatment Unit (SATU), at which point gardaí were called and took a statement from him.
Two weeks later, another complainant came forward making an allegation of being sexually assaulted in similar circumstances to the first man.
Mr Flynn's home was searched twice with, forensics carried out and his work phone seized.
Mr Flynn took his own life on August 18 – eleven days after he had been suspended from ICHH for not informing the board of the serious allegations against him.
On August 26 a third man came forward who said he had secured accommodation through Mr Flynn - the unit was the same one given to the first alleged victim. He claimed Mr Flynn sent him texts asking for sex and transferred him money via Revolut to buy cocaine.
In September, a fourth male made a sexual assault allegation against Mr Flynn. The man had lost his job earlier in the year and, facing the prospect of eviction, turned to the charity boss for help.
Again the complaint related to a taxi being sent to collect the person, which then took him to Mr Flynn's home, where he was allegedly assaulted.
One of Mr Flynn’s alleged victims told RTE in October that he was held by him against his will for two nights and sexually assaulted.
In November it was announced that ICHH was to cease providing services.
The decision came after Mr Justice Brian O’Moore appointed a liquidator to wind down the company after the High Court was petitioned by the Charities Regulator.
A letter from the liquidator Kieran Wallace to the charity’s volunteers confirmed that ICHH will cease providing services to the homeless community.
In the letter, Mr Wallace told service volunteers that he has transitioned services that were provided by ICHH to other homeless charities to ensure that there are no gaps for those in need.