Crocodiles have been seen swimming and sunning themselves at two popular Far North Queensland water holes, wildlife officers say.

A Queensland Department of Environment spokesman said a salt water crocodile had been seen in the upper reaches of Babinda Creek, south of Cairns, last week.

The creek runs into the popular swimming spot the Babinda Boulders and is known as a safe place to swim, with its clear, cold water attracting thousands of tourists to the area.

Environmental officers were also investigating reports of a crocodile west of Kuranda, at Big Sands, although they said it was "unlikely" to be a saltwater crocodile.

The growing crocodile menace in the north of the state had led to claims by some that Government management plans are not working.

"There have been several instances where residents have taken matters into their own hands," the spokesman said.

A 4.3-metre crocodile was found dead on a riverbank on the South Johnstone River at a farm at Wangan, south of Innisfail, in May.

Earlier this year farmer Errol Copley, 69, was fined $500 in a Far North Queensland court after he trapped a 3-metre crocodile at his property at Deeral, south of Cairns.

Senator Fraser Anning, who has just joined Bob Katter's Australian Party, said an urgent cull was needed in the far north.

"It should have been started long ago. I shot lots of them myself," Mr Anning said.

"We've lost too many people to them and they're encroaching on our area and we can't afford to have people taken by crocodiles on a regular basis.

"The crocodile culling that used to go on was fine. It may have gone a little too far but we really need to get it going again now."

When questioned about how many crocodiles he had shot, Mr Anning said he had "never kept count" but there was "quite a lot over the years" in north Queensland and the Gulf country.

He stressed he shot crocodiles before it was made illegal to kill them in the 1970s.

Crocodiles are a protected species in Queensland, with the unlawful taking of a crocodile in the state carrying a maximum fine of $28,383.