Mary Lowry received an anonymous text message after her boyfriend Bobby 'Mr Moonlight' Ryan went missing accusing her of hiding something and warning "We are going to watch you until you crack", the Central Criminal Court has heard.
The court was also told that a scan of Mr Ryan's body revealed he suffered multiple fractures, which were the result of at least four impacts that could have been caused by a traffic accident or blows with a blunt object.
Gda Tony O'Brien detailed to prosecution counsel David Humphries call logs retrieved from phones attributed to Mr Ryan and the man accused of his murder, Patrick Quirke (50).
Gda O'Brien also detailed phone records of Ms Lowry, the victim's son and daughter and the accused's wife among others around the time of Mr Ryan's disappearance in 2011 and the discovery of his body in 2013.
Speaking to defence counsel Edward Doocey, Gda O'Brien revealed that a text was retrieved from Ms Lowry's phone in September 2011.
Written in text shorthand, it said: "You think you are so cool out partying like Bobby never existed. We know you are hiding something and we are going to watch you until you crack."
Gda O'Brien said officers investigated the source of the text but were unsuccessful.
Mr Doocey also asked the witness to take the jury through CCTV footage taken from Ms Lowry's home on the day Mr Ryan's body was found in a disused underground tank on the land she owned at Fawnagown, Tipperary, which was farmed by the accused.
The film showed Mr Quirke arriving shortly after midday in a truck followed about 40 minutes later by his wife, Imelda.
Ms Lowry arrived a few minutes after that and the first garda van arrived at 1.20pm, following a phone call from Ms Quirke to tell gardai about the body.
Mr Quirke, of Breansha- more, Co Tipperary, has pleaded not guilty to the murder of Mr Ryan, who went missing on June 3, 2011, after leaving Ms Lowry's home at about 6.30am.
His body was found 22 months later in April 2013.
The prosecution claims Mr Quirke murdered Mr Ryan so he could rekindle an affair with Ms Lowry (52).
Gda O'Brien also told Mr Humphries that records showed that on the day Mr Ryan's body was recovered, Mr Quirke's phone called his wife's phone at 12.33, a call that lasted eight seconds.
His phone then called a vet some seconds later. Within a minute of that the phone called voicemail and a minute later called Mr Quirke's wife two more times.
The last outgoing call made by Mr Ryan was at about 9pm on June 2 when he phoned his son, Robert.
The following day, Robert texted his father at 9.44am, saying: "Da, you not working today?"
Radiologist Dr Anthony Ryan told Michael Bowman, for the prosecution, that he carried out a CT scan of Mr Ryan's body in May 2013.
He discovered multiple fractures to the head, face and ribs and a fracture to the femur - a bone in the upper leg.
He said the injuries were a result of at least four impacts and could have been caused by a traffic accident or blows with a blunt object.
The injuries to the face were most likely from a direct frontal impact.
Dr Ryan said that when he saw such injuries from a hammer he expected the face to be "depressed" but this injury was not like that, leading him to believe the injury resulted from an object larger than a hammer.
He added that Mr Ryan's face could have impacted with a wall, the ground or a vehicle and that it was hit with "considerable force".
The witness agreed with defence counsel Lorcan Staines that the fracture to the femur would have required a "great degree of force".
He said such fractures were usually caused by falls from a significant height or when a pedestrian was struck by a vehicle.
Dr Ryan said he had seen hundreds of these type of injuries but had never seen them caused by anything other than a fall or a traffic accident.
While the witness said a bat could be used to fracture the femur, the U-shaped nature of the fracture raised a doubt about that possibility.
He added that when a pedestrian is struck by a vehicle they suffer injuries from the impact and then suffer further injuries when they hit the ground or anything else in the environment.
Mr Staines also asked the witness about pieces of concrete that fell on the body when the lid of the tank was removed by gardai using a digger.
Dr Ryan said the fragments could have caused some of the injuries he observed to the ribs, but he did not believe falling concrete caused the fractures to the face and skull or the femur.
Under re-examination, he told Mr Bowman that for a vehicle to cause the injuries he saw it would have to be travelling at more than 30kph but more likely closer to 50kph.
The trial continues.