The description for a three-bedroom house in Regents Park in Sydney's west was listed by online real estate agency PropertyNow - an agent-assisted private sales business that allows home owners to sell their properties on their own.

"This is a most convenient, supreme exclusive peaceful safe quiet friendly neighbourhood location," the listing begins, before noting most neighbours were well respected and "high paid intellectual professionals and businesses (sic) owners are living on this street".

"What you saw [sic] many middle-easterners around shopping, they are doing businesses here but they are not local," it then added.

The original advertisement, which was uploaded to several real estate websites but then amended after it gained traction on Twitter, said "bargain hunters (investors)" or "roaches" should not bother calling the vendor.

The description of the property also included a demographic breakdown, noting the community was made up of "50% Whites, 30% Asians and 8% Sri Lankan/Sub Continents".

PropertyNow licensee and owner Andrew Blachut said the company had zero tolerance for racism and had amended the listing once it was brought to its attention. He said the company had also attempted to contact the vendor.

"PropertyNow and myself have zero tolerance for any form of racism," he said. "We have guidelines and rules for vendors [who write their own property advertisements] ... and attempt to educate users about the need for care in listing descriptions.

"We do monitor listings daily very closely and with a great deal of resources and expense but we are not infallible," he said.

While all staff were responsible for quality control, he had decided to appoint a specialist staff member who would be responsible for monitoring all listings regularly.

The home is on a 572-square-metre block.

Local agent Sazer Younis of LJ Hooker Chester Hill said he was surprised to hear that a vendor had included these details in their property listing.

"Regents Park is definitely a multicultural community," he said. "It's more than welcoming ... and the people live in harmony together.

"It just doesn't make sense to me why someone would say that?"

"I saw the ad and had a read and I just thought wow, what were they thinking?" said fellow local agent Frank La Malfa of Phillip Daidone Realty.

Mr La Malfa, who has worked in the area since 2002, said the welcoming community was made up of a mix of people from Asian, Middle-Eastern and Anglo backgrounds.

"Lots of people buying into the market here are from different cultures. We sell houses to people of all backgrounds."