The State Government will delay awarding the contract for catching and killing sharks off Perth beaches after claims professional fishermen who tendered for the work had been threatened by protesters.
Police have confirmed they are investigating threats against professional fishermen and Fisheries Minister Ken Baston.
They did not indentify the fishing contractor or reveal details of the threats, saying they "treat these type of incidents seriously".
There has been a furious backlash to the Government's plans, announced last month after seven people were killed in WA waters in three years.
Under the Government's plans, commercial fishermen will be contracted to set and monitor drum lines off Perth and South West beaches to kill sharks bigger than 3m.
In light of the police investigation, it is understood Premier Colin Barnett will announce as early as today that the Government has no option but to delay plans to catch sharks off the metropolitan coast.
It is believed the Government will push ahead and award the winning tender for the South West drum-line contract as planned.
Opponents of the policy have vowed to take "direct action" against it, with one website warning professional fishermen who carry out the work will "face the public's wrath".
A Facebook page - set up by hardline environmentalists - also lists the names and numbers of fishing businesses believed to have tendered.
"Whoever the killers turn out to be they can expect MASSIVE opposition from an outraged public," one post says.
"Pickets and boycotts will be effective stratedgys (sic) too (sic) name and shame . . ."
Activist Simon Peterffy said the website was a forum through which critics of the plans could engage but it was never meant to incite threats against or harassment of fishermen or the Government.
A man opposed to the shark cull policy was charged this month after allegedly using a hammer and graffiti to attack Mr Barnett's Cottesloe electorate office.
Mr Peterffy said he supported only the use of "non-violent" means to protest against the plan.
"If there have been death threats or anything like that, we think it's abhorrent," Mr Peterffy said. "We're totally committed to non-violence and if anyone did something like that, it would only ruin a popular public movement."
The delay is a further inconvenience to the Government after it was unable to meet its self-imposed deadline of having drum lines set by January 10.
The Government had been hoping to name the winning tenderers within days. It is understood the Premier is frustrated the latest delay means Perth beaches will not be protected as the Government had intended.
Thousands of protesters rallied at Cottesloe beach this month to express their opposition to shark culling.