Wagga Wagga City Council, supported by the police, investigated reports horses had been butchered at the property and their carcasses left in a dry creek bed.

The council inspected the property and said it became clear the slaughtering of the horses had been occurring for a long period of time.

Various dumps of carcasses were found throughout the property, totalling more than 500 dead horses.

Some carcasses were no more than skeletal remains while others were killed recently.

"A lot of agencies came together to co-operate on ensuring that people who do an extraordinarily wrong thing have been identified and held to account," Wagga City Council general manager Peter Thompson told reporters on Wednesday.

Mr Thompson said the owner of the property would not face any repercussions from the council as it is out of their power.

The council began an investigation two months ago, after a tip off by an anonymous informant, led them to confirming and discovering the carcasses.

Elected councillors were only made aware of the grim discovery during an operational meeting on Monday.

Australian Associated Press