RSL LifeCare, the charity nursing home operator under investigation for the $2.5 million in "consulting fees" paid to its directors, donated a total of nearly $1500 to the NSW Liberals between 2015 and 2016, according to Electoral Commission filings.

Guidelines from the Australian Charities and Not-for-profits Commission warn charities not to support political candidates or parties because having a political purpose can cause them to be disqualified.

The state opposition called for the money to be returned.

"Thousands of good-hearted people who support RSL LifeCare will be shocked to hear that money was being funnelled off to the Liberal Party," said Opposition Leader Luke Foley. "The RSL should be above party politics.

"The Liberal Party should never have accepted money from a charity."

RSL LifeCare, which was founded a century ago on volunteer labour, operates 30 nursing homes around NSW.

It receives hundreds of thousands in donations each year, composed of small gifts from RSL sub-branches, women's auxiliaries and independent charities each year.

It is owned by the NSW RSL, which has been rocked by revelations that 10 of the charity's directors, many senior figures in the RSL, had been dividing annual payments of up to $370,000 between them since 2010.

???But a spokeswoman for RSL LifeCare defended the $1450 donations, which were payments for attendance at two Liberal party fundraising breakfasts featuring former premier Mike Baird and Premier Gladys Berejiklian.

"The aged care industry is one of the most heavily regulated sectors in Australia," the spokeswoman said. "RSL LifeCare's management team needs to keep on top of public policy trends and developments."

The spokeswoman said about 10 senior managers paid about $75 each to "learn about the government's plans for the [aged care] sector".

Fairfax Media revealed yesterday that one of the RSL LifeCare directors to receive money was Jim Longley, the CEO of the $2.7 billion Department of Ageing, Disability and Home Care.

Before he became one of NSW's most senior bureaucrats, Mr Longley was the Liberal MP for Pittwater for a decade until 1996 and is a former aged care minister.

The Premier referred questions to the NSW Liberal Party, which said the payments were properly disclosed.

The entire NSW state council of the RSL has stood aside while the consulting fees and other financial irregularities are investigated. The payments also triggered the resignation of the RSL's national president, Rod White, last month.

State law forbids charities from remunerating directors unless they have express written permission from a minister.

A preliminary review by forensic auditors KordaMentha said it appeared that no permission had been given, but the state government has declined to comment citing an investigation into the matter by NSW Fair Trading.

RSL LifeCare said directors were paid for work that went beyond their roles on the board and that payments were allowed under its constitution.