The beheading of a crocodile at a popular far north Queensland beach is a sign people have lost faith in the state government's regulation of the animals, federal MP Bob Katter says.
Environment Minister Andrew Powell said it appeared the 2.5-metre crocodile had been caught on a baited stainless steel hook, which was found in its torso.
The body was discovered by local rangers on Monday at Kewarra Beach, north of Cairns.
They were setting traps to find and relocate a crocodile that last week killed a pet border collie just metres away.
Tests are determining whether the beheaded crocodile was responsible for the attack.
Mr Powell warned people who illegally kill crocodiles, which are a protected species, could be fined more than $24,000.
He said the state government was committed to a new crocodile management plan.
The plan prevents the animals from entering areas used for swimming and water activities, removes them from boat ramps and marinas, and removes any crocodile which exhibits unprovoked aggressive behaviour to a human.
"We will take action to address this issue ... but it is not safe or appropriate for anyone to take part in this sort of behaviour," he said.
But Mr Katter said the slaying of the crocodile showed people had lost faith in the government's ability to manage the animals.
"If you think you can pass laws which put Queenslanders in danger while you are sitting in manorial comfort in Brisbane, then you're wrong," he told AAP on Tuesday.
"People will take the law into their own hands and you cease to be the government.
"All I can say is, 'surprise, surprise'."