A Sydney woman is facing 74 separate charges of bribery and corruption after she allegedly defrauded one of the nation's biggest banks to the tune of $26.7 million.

Key points: Ms Rosamond allegedly bribed the NAB's former chief of staff with luxury travel and renovations

Ms Rosamond allegedly bribed the NAB's former chief of staff with luxury travel and renovations Prosecutors claim she secured lucrative contracts with NAB for her company

Prosecutors claim she secured lucrative contracts with NAB for her company It is alleged Ms Rosamond's invoices to NAB were as high as $3.3 million

Helen Rosamond, 44, allegedly paid millions of dollars in kickbacks, which included first-class air travel, to secure lucrative contracts from the National Australia Bank (NAB) for her company, the Human Group.

Ms Rosamond was arrested at her Potts Point home in March following a year-long investigation by detectives from the NSW Police Financial Crimes Squad.

The investigation, codenamed Strike Force Napthali, centred on $40 million worth of corrupt commissions allegedly paid to the bank between 2013 and 2017.

In court today, prosecutors presented Deputy Chief Magistrate Michael Allen with a new charge certificate alleging Ms Rosamond had committed an additional 12 fraud offences worth $19.4 million.

It is alleged that between 2014 and 2018, Ms Rosamond submitted invoices "for non-bank expenditure" as high as $3.3 million, along with seven individual invoices amounting to close to $10 million and several others for hundreds of thousands of dollars.

Lawyers for the Director of Public Prosecutions told the Downing Centre Local Court the new charges followed a forensic accountant's report covering 10,000 pages.

It is now alleged the total value of Ms Rosamond's corruption and fraud has cost NAB $26.7 million.

Detectives alleged Ms Rosamond worked in partnership with Rosemary Rogers, the former chief of staff to NAB'S former chief executive.

It is alleged she and her company sent the former NAB chief of staff on a $620,000 holiday to the United States, a $250,000 trip to Fiji and a $160,000 holiday to Europe, and funded $700,000 in renovations to Ms Rogers' homes.

The charge sheet alleges there were other purchases, including a BMW worth $172,000.

Ms Rogers was arrested in March and faces 57 corruption-related charges.

Ms Rosamond was excused from attending court on Thursday.

She remains on bail with $200,000 surety and a night time curfew and has surrendered both her British and Australian passports.

Her case is set to return to the Downing Centre on January 30 next year.