A Northern detective team was assigned to the investigation, but after a month of digging they found no evidence of foxes in Tasmania.

Despite this, the state government continued to claim that criminals had illegally smuggled fox cubs into the state.

In the 14 years following the police investigation, the government spent about $50 million trying to rid the island of the rumoured pest population.

The controversial Fox Taskforce went on to uncover three fox carcasses, body parts, scats and other material in Tasmania.

Scientists have disputed the legitimacy of the finds.

This week, Tasmania Police said it would consider whether to investigate allegations of criminality in the Fox Taskforce.

Retired Detective Inspector MICHAEL OTLEY - head of the 2001 fox cub importation theory investigation - spoke to crime reporter CHRIS CLARKE about the theory, the police work and the politics.

CC: In June 2001 you started an investigation into the theory that foxes had been smuggled into Tasmania and released. What was your brief?

MO: We received a brief (from the state government). It said that an informant had claimed that (deer) shooters had brought foxes into the state.

CC: When requested that you investigate the fox cub importation theory, what did you think?

MO: At that time, I didn't think anything. Upon being given that information, I commenced an investigation in conjunction with a detective sergeant and two detective constables. Obviously I was open-minded. But I could establish no evidence to support the allegation that (deer) shooters had imported foxes into Tasmania. I further believed that there was no evidence to support foxes in Tasmania, other than the one killed at Burnie and the other in the North - both came off transport containers from South Melbourne. We were also advised that devils and quolls would have certainly interfered with the breeding of foxes.

CC: What did you find during your investigation?

MO: We interviewed people linked to (deer) shooters. They didn't know anything. (What was thought to be a fox den) was excavated. We certainly found no evidence of any foxes after excavation of the site.

CC: What lengths did you go to to investigate that theory?

MO: We spoke to the initial informant from the Southern district. His information could never be corroborated by any fact or evidence. We spoke to a number of shooters and property owners in the North. There was never any suggestion of foxes.

CC: What hampered that investigation?

MO: Initially, Parks and Wildlife didn't want to reveal who their informant was. After the directive ... (the informant's name) was given to us. Obviously Parks and Wildlife wanted to establish the existence of foxes. From the inquiries we did, it just wasn't true.

CC: How did it hamper the investigation when the government wouldn't reveal their source?

MO: It took five or six working days to establish that. We had to be be very careful about who we spoke to.

CC: How important is a chain of evidence in an investigation?

MO: It's extremely important to establish the bonafides of the exhibit to see that it hasn't been tampered with - so that conclusions can be given more accurately, rather than people just saying something.

CC: Was there a clear chain of evidence when you investigated the fox cub importation theory?

MO: There was no evidence. Only people saying they saw a fox and a lair on a property at Longford.

CC: How much influence did the government have in that investigation?

MO: My direct command was the commander and the commissioner. There was one specific allegation. There were a number of sightings after, but we didn't go any further than that.

CC: How did the government react to your findings?

MO: I can't say because I don't know. There was certainly further information coming in.

CC: How did you feel when the state government continued to spruik the fox cub importation theory, despite your evidence suggesting no such crime occurred?

MO: They still considered that information to be correct. There was no corroborative evidence, just hearsay.

CC: Are all biosecurity-related police investigations conducted in that manner?

MO: There was (a similar investigation) in the '60s with the rabbit population on Flinders Island. But (detectives) do normal investigations. Our expertise, in my view, was a lot more professional than Parks and Wildlife at that time.

CC: Do you believe the fox cub importation theory was a legitimate crime that had occurred?

MO: I can't establish any evidence of it. Therefore, no.

CC: Was there a fox population in Tasmania in 2001?

MO: No.

CC: Are there currently foxes in Tasmania?

MO: No one can ever say that there aren't any foxes. But there was certainly no human involvement in importing foxes.

CC: Any further comments?

MO: Because of the reduction in devils and quolls, I would have thought we would have seen significant evidence of foxes, like the killing of livestock and poultry done by animals other than native animals.