Dame Marie cost taxpayers $254,464 in the six months to December, putting her on track to exceed the $496,234 she received in benefits in 2015-16, according to figures released by the Department of Premier and Cabinet on Thursday.

The only former governor to receive public support beyond car transport, her expenses were close to double the costs incurred by former premiers Nick Greiner and Bob Carr and eclipsed the amounts spent by Barry Unsworth and John Fahey.

Mr Greiner, who is the director of numerous companies, received $151,224 in benefits, which will be reduced by $23,000 at the end of the financial year to take into account his personal contribution to office rent.

Mr Carr received $153,033, while Mr Fahey and Mr Unsworth – whose shorter terms as premier render them ineligible for staff – claimed $8833 and $728 respectively. No other former premier claimed expenses.

The Baird government struck a special arrangement with Dame Marie upon her retirement as governor in 2014 to cover the cost of her ongoing community activities and engagements.

The bill includes $80,000 in staff salaries, $65,000 in driver salaries, $97,000 in office rent, $12,000 in car transport, $623 on telephones and $1500 on other office costs.

Dame Marie has offered to move to cheaper office accommodation than that which she occupies at Blair House, a footnote said, "however at this stage the department has been unable to identify suitable options".

A spokeswoman for the Department of Prime Minister and Cabinet did not respond to a question about what constituted suitable accommodation, but said Dame Marie's offer to move was a standing offer.

"She is very conscious of the need to minimise public expenditures," the spokeswoman said.

Public support for former office holders was at the discretion of the premier and the arrangements for Dame Marie had been modelled on the changes introduced by Mr O'Farrell in 2012, the spokeswoman said.

"Dame Marie Bashir held the office of the Governor of NSW for 13 years, making her the state's second longest-serving governor.

"Since retiring from the Office of the Governor in 2014, Dame Marie has continued to be heavily involved in the public and community life of NSW, by supporting a number of community organisations and engaging in community activities."

The other former governors – Rear Admiral Sinclair and surviving spouses Lady Cutler and Lady Martin – incurred a combined total of $590 for car transport. The current governor, David Hurley, has an annual salary of $467,640.

Barry O'Farrell wound back entitlements for former premiers in 2012, with a scheme that would, in future, only give benefits to premiers who had served at least five years and were limited to one year after leaving office.

Existing long-serving former premiers were no longer compensated for air travel, the provision of cars and drivers was reduced and staff entitlements were reduced from two people to one.

"Entitlements for former premiers have long been a source of community discontent and I am determined to ensure taxpayers get value for money," Mr O'Farrell said at the time.

Mr O'Farrell had wanted the cuts to apply to those who had already left office but former premiers Nick Greiner, Bob Carr and Neville Wran threatened legal action if their entitlements were not guaranteed for life.

Nevertheless their entitlements were more than halved under the new rules and the bill to taxpayers was reduced from $1.6 million in 2010-11 to $660,000 in 2012-13.

Since then, the costs have gradually increased, rising to $1.1 million at the end of last financial year.

The department spokeswoman said the provisions afforded to Mr Carr and Mr Greiner enabled them to continue to participate in public life.