Sex, blowflies and a lovelorn farmer who sought advice from a newspaper agony aunt before allegedly murdering his love rival: it is the murder case transfixing Ireland.

Patrick Quirke, 50, is accused of killing Bobby Ryan, a DJ known as Mr Moonlight, in 2011 and hiding his body for two years in an underground tank on a farm in County Tipperary.

The trial, which started last month, has at times eclipsed Brexit with banner headlines about Quirke’s alleged plot to rekindle a “seedy affair” with Mary Lowry, who had left him and started a relationship with Ryan, 52.

On Friday a jury of six men and six women at the central criminal court in Dublin heard that Ryan’s body showed evidence of multiple injuries that could have been the result of a road collision or a serious assault.

It was the latest revelation in a case that has focused on grisly forensic evidence and testimony about romantic rivals in Fawnagowan, a rural Tipperary townland 120 miles (190km) south-west of Dublin.

Quirke denies murdering Ryan.

Lowry, 52, has testified that she began an affair with Quirke in 2008, a year after her husband died of cancer. Quirke is married to her late husband’s sister and helped with Lowry’s farm and finances.

Lowry said she felt vulnerable as a widow and sought comfort but found Quirke to be “overpowering” and “intimidating”. He badgered her for money and she was ashamed of the relationship, she said.

She ended the relationship in the summer of 2010. Soon after she met and started dating Ryan, who helped her obtain tickets for an All-Ireland hurling final. He was a “breath of fresh air” and she loved him, as did her children, she testified. “What more would you want from a relationship?”

Quirke resented Ryan and confronted him, saying “she’s mine”, Lowry told the court.

In February 2011 the Dear Patricia advice column in the Sunday Independent newspaper published an anonymous letter from Quirke complaining that he was a married man who had been ditched by his girlfriend.

Ryan went missing on 3 June 2011 after leaving Lowry’s home at about 6.30am. Lowry said she saw Quirke at her farm at about 8.30am and found it unusual he would be there so early. She said he seemed “hot and sweaty and bothered looking”.

Prosecutors allege Quirke killed the DJ and hid his body in an underground run-off tank on Lowry’s farm, hoping to then rekindle his affair with her.

Quirke told the court he had accepted Lowry’s new relationship and was mystified by Ryan’s disappearance. “I asked questions and like everyone else I had a hunch what happened,” he said. “Everyone had notions he was attacked. Did he leave for Spain?”

On 30 April 2013 Quirke called police to say he had discovered a decomposing body in an underground tank.

John Manlove, a forensic entomologist, told the court the presence of common blowfly larvae in the body’s chest cavity suggested the tank had been opened several weeks earlier.

The trial continues.