Todd Barclay refused to co-operate with police three times

Former National MP Todd Barclay refused to co-operate with police on three distinct occasions during the fresh investigation into his alleged bugging of staff.

With this year's election campaign underway, Barclay was again refusing to be interviewed by police, refusing to allow access to evidence held by Parliamentary Services and refusing to allow police to search his electorate office.

The refusals all took place after party leader Bill English told the Herald: "Todd Barclay will remain an MP until the election and will continue to carry out his usual duties and represent his community in that time."

The fresh details of Barclay's refusal are contained in documents released through the Official Information Act from the second investigation into allegations of Barclay secretly recording staff.

The second investigation came after English admitted he had been told by Barclay that the secret recording existed - a detail police could not prove in its first investigation.

The detail was also not proved in the new investigation, although detectives said there was "circumstantial" evidence that he had done so.

Barclay is now gone from Parliament, having announced he would not seek re-election after publicly wrong-footing English on the issue.

The OIA papers detail how police pursued a line of inquiry sparked by reports from NZME's NewstalkZB political editor Barry Soper.

Soper had reported that Barclay had used CCTV cameras fitted with audio recording facilities to pick up comments made by electorate secretary Glenys Dickson, a National Party stalwart in Southland who worked for English for 20 years.

Detective sergeant Greg Baird, in his report on the case, wrote that detectives sought details of CCTV systems capable of picking up audio recordings, and sought paperwork relating to the refurbishment of the electorate office after Barclay took over.

The police documents show that Barclay refused to grant consent to Parliamentary Services which would have opened up new lines of inquiry.

Baird recorded that police again pursued Barclay for an interview and were again knocked back.

And he continued to refuse permission for police to search his electorate office.

The police assessment on whether to lay charges included an assessment of evidence that would be provided by English. Police assessed him as a "credible" witness.

In a section headed "Beyond Reasonable Doubt", Baird assessed the case against Barclay and said it could hinge on an explanation from the MP.

"This element would largely depend on any explanation offered by Barclay."

The office writing the assessment said other witnesses aside from English were also credible and there were also statements from Barclay which suggested confirmation of the recording.

Baird did not offer a recommendation around prosecution, saying he was told not to do so when writing the report.

The police inquiry did not just focus on Soper's report of a CCTV recording but also included consideration of Barclay using a covert recording device disguised as a pen, coffee cup, sunglasses, pot plant and other office items. Officers paid particular attention to a pen she was given by Barclay.

Detectives quizzed Dickson on whether any of those items had turned up in the office, including showing her photographs of the disguised devices.