Monster's death to spark aggro croc battle

Younger crocodiles living in the Fitzroy River in central Queensland could become more aggressive following the shooting death of a massive 5.2m reptile.

Giant 5.2m saltwater crocodile has been found shot dead in the Fitzroy River in central Queensland. (AAP) Source: AAP

The shooting death of a 5.2m crocodile has created a void in a central Queensland river that could result in younger males becoming more aggressive as they battle for dominance, wildlife officers say.

Police and the state government are investigating after the reptile was found with a bullet in its head in the Fitzroy River, near Rockhampton, on Thursday.

Department of Environment southern wildlife operations director Michael Joyce said the remaining male crocodiles could act differently and become more hostile as they establish who will rule next.

5.2 metre salt water crocodile shot dead in Queensland. Source: Twitter: Queensland Police

"They don't necessarily become more aggressive with outsiders," Mr Joyce told AAP on Friday.

"But we would expect people to be croc-wise in croc country and be extra vigilant."

Mr Joyce says wildlife officers will monitor the river to see what transpires and who becomes the next dominant male.

"The whole thing could be over in 24 hours; at other times it could take months to see a slight move in the population," he said.

5.2 metre salt water crocodile shot dead in Queensland. Source: Twitter: Queensland Police

Locals are being urged to notify the department of any crocodiles spotted in the river and elsewhere across Queensland, even if they are seen regularly.

The monster reptile found on Thursday was taken to the nearby Koorana Crocodile Farm, where it will be buried once a necropsy is carried out.

Farm owner John Leaver says a 5m-long crocodile has not been caught in Queensland for 20 to 30 years.

"There may have been some others shot in the wild that we don't know about, but from my recollection, over the past three decades this would be the largest," he told AAP on Friday.

Mr Leaver, who ran a crocodile removal service across the state for 20 years, said the largest reptile he ever caught was 4.95m in the late 1980s.

It is believed the 5.2m reptile had been dead for a few days before a member of the public spotted it floating and notified environmental officers.

Mr Joyce said it was estimated to be between 80 and 100 years old.

"It is on the larger end of the scale, there's no doubt about that," he said.

"There are not a lot of crocodiles over 5m."