An aged care facility on the NSW south coast is under fire after maggots were found in a patient's head.

An elderly resident in an increasingly substandard NSW aged care facility has been hospitalised after maggots were found in his head.

The disturbing discovery comes months after Bupa's Eden facility, on the NSW far south coast, was sanctioned by the government because residents were at "immediate and severe risk".

Federal Aged Care Minister Ken Wyatt said it was "totally unacceptable and concerning" the facility had a resident with maggots in a wound so quickly after it was inspected by the newly beefed-up regulator the Aged Care Safety and Quality Commission.

"In this day and age, with all of the attention given to care being centred on individuals, we shouldn't see this occurring," Mr Wyatt told reporters in Sydney on Tuesday.

"I'm disappointed they've allowed this to happen."

The discovery was made between February 26 and 28 and sparked an "urgent" request by government agencies for information from the facility, a commission spokeswoman told AAP on Tuesday.

Bupa's chief operating officer Carolyn Cooper apologised to the resident and his family.

"I have personally spoken to the family today and understand their disappointment," she told AAP in a statement on Tuesday.

Results from government inspections show a decline in standards at the Eden facility over the past few years.

In 2013, the facility, which was then known as Eden Community Care, met all 44 of the accreditation standards.

Those standards remained intact in 2016 after Bupa began running the home.

But in August 2018 inspectors found five were no longer being met.

The commission significantly stepped up the schedule of unannounced visits in this time.

But conditions continued to deteriorate and, by November, the government refused to sign off on 22 of the necessary standards.

The next month the commission reported "critical deficiencies at the service contributing to serious and detrimental failings" including in human resources, clinical care, medication management and health and personal care.

The facility was sanctioned with its commonwealth funding stripped back. Bupa was ordered to recruit and train new staff to address the shortcomings.

The facility will remain under sanctions until June 7.

But this latest incident means investigators will again return to monitor the home, Mr Wyatt said.

The man has since returned to the facility and Ms Cooper said immediate action had been taken to improve wound management and provide further training to staff.

But the government will continue to lobby the company on a "raft of matters" that make it clear the government is concerned, the minister said.

"Australia expects aged care providers to shape up and provide the level of care that is needed."

All visits by commission investigators are now unannounced, the spokeswoman said.

"We are seeking to use information from a range of sources, including feedback from consumers, to target areas of highest risk," she said.