A purported ‘friend’ of a prison guard identified as a potential suspect in a missing person probe claimed he was the victim of a “witch-hunt” and suggested that his ex-wife come under similar media scrutiny.

An exchange of text messages between someone calling themselves ‘Nigel’ and a crime reporter who suspected they were actually talking to David Benbow, who would later be charged with murdering missing man Michael McGrath, have been relayed in court today.

Benbow denies killing his friend 49-year-old McGrath on Monday, May 22, 2017 and is standing trial at the High Court in Christchurch.

No body and no gun have ever been found.

Benbow’s legal team has warned the jury that the police had “investigative bias”, with ex-partner Joanna Green immediately pointing the finger of blame at him.

Today, former Stuff reporter, now NZME senior crime journalist Sam Sherwood has been giving evidence and telling the jury about how he stumbled across a cellphone number for Benbow during his reporting.

Nearly a year after McGrath’s disappearance, and Benbow had been named by police as a person of interest in their missing person inquiry, which saw him named in various news articles, his Candys Rd property surfaced for sale.

By then another reporter had door-knocked Benbow’s house on a couple of occasions, with the Corrections officer saying he felt he was the victim of a witch-hunt.

Sherwood found the property listed online and when sifting through associated documents found Benbow’s cellphone number.

Christchurch builder Michael Craig McGrath, 49, was last seen at his home in Halswell, Christchurch, in May 2017.

The reporter called Benbow and asked if he had anything to say. He made it very clear he didn’t want to comment, Sherwood told the court.

He also sent him a text message, giving Benbow the opportunity to speak about what he had been going through and that he believed he was the victim of a witch-hunt.

Two days later, on March 16 2018, Sherwood received a text from a number he didn’t recognise, the court heard, which said they were a “good friend” of Benbow and claimed that it was Green who “triggered” the police investigation, saying she had a chronic drink problem, and that she had been in a new relationship with McGrath.

Sherwood asked who he was speaking to and they replied, ‘Nigel’. They went on to allege that Green could be violent and was a person of interest herself. They said police had never searched her house or car.

They advised the reporter visit her workplace, get her number plate, and take her photo.

NZME crime journalist Sam Sherwood gives evidence at the Michael McGrath murder trial at the High Court in Christchurch. Photo / Pool

When Sherwood asked how Benbow was coping, ‘Nigel’ said his life had been turned upside down after “300 days of no evidence” and that “David isn’t that clever”.

When Crown prosecutor Barnaby Hawes asked who he thought he was communicating with, Sherwood suspected it was Benbow himself.

Later, after speaking with a colleague, he took screenshots of the conversation and provided them to police.

Asked if he operated independent from the police, Sherwood replied: “One hundred percent, yes.”

Detective sergeant Joanne Parks today told the court that phone records linked the cellphone number of ‘Nigel’ to Benbow’s Candys Rd property.

Under cross-examination by lead defence counsel Marc Corlett KC, Sherwood accepted there had been intense media interest in the case and that there were numerous articles from various media outlets that were “riddled with references” to Benbow.

The reporter also accepted sending regular text messages to Benbow over the following months, asking if he was ready to talk.

While the Crown accepts there is no body, no murder weapon, and little forensic evidence in the case, it says there is a strong circumstantial case consisting of many threads that, when taken together, show Benbow is guilty of McGrath’s murder beyond reasonable doubt.

They say Benbow had the motive, means and opportunity to kill McGrath.

The trial, before Justice Jonathan Eaton, continues.