When gardaí asked murder accused Patrick Quirke why he had searched the internet for "body decomposition timeline" he told them his son had died and added: "That's all I'm saying."
Gardaí also put it to Mr Quirke that he had carried out similar internet searches before his son's tragic death in August 2012 but he denied that this "blew out of the water" his explanation.
On the final day of prosecution evidence, it also emerged that gardaí sent the sub aqua unit to Ardmore in Waterford after a water diviner told them they would find Bobby Ryan's body there.
Farmer Patrick Quirke (aged 50) of Breanshamore, Co Tipperary, has pleaded not guilty to the murder of Bobby Ryan, a part-time DJ known as Mr Moonlight. Mr Ryan went missing on June 3, 2011, after leaving his girlfriend Mary Lowry's home at about 6.30am.
His body was found in an underground run-off tank on the farm owned by Ms Lowry and leased by the accused at Fawnagown, Tipperary 22 months later in April 2013. The prosecution has claimed Mr Quirke murdered Mr Ryan so he could rekindle an affair with Ms Lowry (aged 52).
Garda Kieran Keane told Lorcan Staines SC, for the defence, that gardaí sent the sub aqua unit to Ardmore, Co. Waterford after a water diviner said the body would be found there.
He said that his understanding is that the diviner uses "psychic powers" using two rods over a map. He told prosecution counsel, David Humphries BL, that he does not believe gardaí went looking for the diviner but that they came into possession of the information.
Inspector Seamus Maher today told prosecution counsel Michael Bowman SC that gardaí arrested Mr Quirke on suspicion of Mr Ryan's murder on June 19, 2014, and interviewed him the following day at Tipperary Garda Station.
During those interviews, Det. Insp. Maher agreed with counsel that gardaí asked Mr Quirke about a computer hard-drive labelled as KKPQ1 which was seized from Mr Quirke's home in May 2013 and which gardaí said they had identified as belonging to the accused.
A computer expert, they told him, had identified searches relating to the limitations of DNA evidence carried out some time before September 2012 and other searches relating to human decomposition on December 3, 2012. There was also evidence, they told him, that someone had visited sites containing information about DNA and decomposition.
Gardaí asked him if he could eliminate his wife and children as the people who carried out those searches. He responded that he didn't know what they meant. He also said he was not familiar with "in private browsing" when gardaí asked if he activated a private browsing session when carrying out the searches.
They asked if there was any explanation for those searches and he replied: "My son had recently died. That's all I'm saying." Gardaí sympathised with him, telling him they can't imagine what that was like.
He responded that the gardaí "don't believe a word I say". He said they had charged him with assaulting Mary Lowry but didn't properly investigate it and the charges were later dropped.
Gardaí told him those charges were brought by Tipperary gardaí and his interviewers had nothing to do with that. He responded that they all come under the same umbrella and he finds it hard to believe that gardaí will listen to him.
His interviewers asked him why he looked at an article on the "limitations of DNA evidence" but he said he couldn't remember.
Gardaí then put it to him that he was searching over a prolonged period on a number of occasions for terms relating to decomposition because he knew where Bobby Ryan's body was and was trying to establish what condition it would be in.
He responded: "Why would I need to do that."
He said that if he knew where Bobby Ryan was all he would have to do is open the lid of the tank and look in. He said it wouldn't make sense for him to search for decomposition on the internet when he had unlimited access to the tank at all times.
Gardaí suggested that someone might see him and ask questions but he said that doesn't make sense and that given the remote location he could have checked it when nobody was around. "You wouldn't do it on a Saturday morning," he said.
He told gardaí they weren't taking on board anything he was saying and added: "What I say does stand up and make sense and you say, 'no, no, no, it wasn't like that Pat'."
He further described as a "load of crap" the theory that he alerted gardaí to the body because he wanted to be "in control" and didn't want it to be found by someone else after his lease on the land came to an end two months later. He asked them why he would bring this "nightmare" on himself, his relationship with Mary Lowry coming out into the open.
He said repeatedly that the garda theory doesn't make sense and denied that the discovery was staged. If he wanted to, he said, he could have remained on the land for another two years and the decision to leave was his own.
Gardaí later returned to the internet searches and confirmed that Mr Quirke's son Alan died on August 4, 2012. Gardaí said they had reviewed the evidence and found a search for "body decomposition" on July 25, 2012. They said this "blows out of the water" his explanation.
Mr Quirke said his explanation wouldn't account for every search. He said the previous search does not "blow out of the water" his explanation for the searches on December 3, 2012.
Gardaí also asked Mr Quirke about what he saw when he first looked into the tank. In previous voluntary interviews, Mr Quirke said he went to the tank to draw water using a suction tanker so he could agitate slurry in a nearby shed.
As he was sucking water out of the tank he saw something resembling a carpet or an inflatable doll. Pointing to a photo of the tank gardaí asked him how he would have seen a body and why he would have looked into the tank.
He said he first thought he saw something that looked like a carpet and then looked closer. Gardaí said an engineer had examined the tank and found it to be porous and incapable of holding water.
When he looked in, they said, he would have seen it did not contain water and had no reason to investigate further. Mr Quirke said he had explained this "in great detail" already and that he saw something in the tank that "warranted further investigation".
When gardaí asked why he phoned his wife when he realised it was a human body he said: "Obviously I wasn't thinking straight."
The interview turned to the subject of the accused's affair and break-up with Mary Lowry. He said he has "no real resentment of Mary" and added that he is not the one, "going around saying what I think of her".
He said the best reaction was to say nothing and added: "I'm constantly trying to defend myself." He said he felt pressure and added: "Why on earth would I have discovered that body? Why on earth would I have brought that on myself?"
He asked gardaí why would he murder a man and then show people where the body was, particularly in April, one of the busiest farming months of the year. He said: "Why not do it in January if this was thought out?"
Justice Eileen Creedon told the jury of six men and six women that they will not be required again until Thursday.