Under cross-examination from the lawyer acting for Peter Gibbons and Graeme Scott, Mr Van Essen admitted he did believe the men "should not be allowed to continue to operate they way they are".
The long-term ACC recipient was the first of 16 people to present their objections to the men's annual application to renew their licences at the first day of a three-day tribunal in Dunedin before Gary Harrison, the registrar of private investigators and security guards.
All the objectors' involvement with the men was in relation to ACC dealings.
Under questioning from Steve Bonnar, Mr Van Essen said all of the objectors felt they were unreasonably targeted by the pair when they were contracted to work for ACC's fraud unit.
However, he denied the objections were part of an orchestrated campaign.
"I'm not in some sort of conspiracy. I'm an injured person who has been targeted by malicious information which has been taken further by these guys and ACC and others."
But Mr Harrison said he had never seen such a degree of co-ordination from so many objectors to the same applicants at the same time.
At least five of the 16 letters of objection were worded the same and responses to further questions he asked objectors were also worded similarly.
"The inference in that regard is inescapable, really."
The first day of the hearing drew to a close after Mr Bonnar countered a claim from Mr Van Essen that Mr Scott had worked for a period as a private investigator without a licence, by pointing out that under the relevant legislation those seeking information on behalf of a crown entity (in this case ACC) did not need a private investigator's licence.
Mr Bonnar also negated Mr Van Essen's claim Mr Scott was still a sworn police officer when he started working for Mainland Information Consultants, by producing evidence of his earlier official retirement from service.
Mr Van Essen made several allegations against Mr Gibbons, including that he had provided unsubstantiated and misleading information to police that he (Mr Van Essen) had used a document (a medical certificate) for pecuniary advantage and made a false statutory declaration.
He said ACC and the private investigators' suspicions that he did not declare earnings from work he did at a local school, had regularly bought computer equipment through his own company, ran websites dealing in pornography and did not declare income from selling Zippo lighters on-line were ill-informed, misleading and, in some aspects, completely fabricated.
"In Mr Gibbons' fantasy, I was running pornography sites all over the world and stashing the dollars in the Bahamas. There has been no fraud. I have been totally open with ACC."
He had been cleared in each of four separate investigations by ACC, he added.
"All of that was documented with ACC, the school and me and [Mr Gibbons] could easily have come by the information if he had bothered to look, or ask, for it."
Mr Harrison, an Auckland barrister, said his job was to decide if individuals were fit to hold licences.
"In this case, one of the most important issues would be whether there was a reasonable basis for the actions of Messrs Scott and Gibbons and the other agencies as well."
