NEW YORK: US prosecutors unveiled more charges against a billionaire Macau real estate developer and three others accused of engaging in a bribery scheme involving a former president of the United Nations General Assembly.

The charges were in an indictment in Manhattan federal court against five people including John Ashe, a former UN ambassador from Antigua and Barbuda who was General Assembly president from 2013 to 2014.

Prosecutors previously said Ashe took more than $1.3 million in bribes from Chinese businessmen including Ng Lap Seng, who has a $1.8 billion net worth and developments in the Chinese territory Macau.

Ng, 68, who prosecutors say paid Ashe more than $500,000 to seek UN support of a conference centre in Macau, had previously been charged on Oct. 6 with bribery conspiracy and bribery charges.

Ng now faces two additional counts including money laundering, as well as his assistant, Jeff Yin, and Francis Lorenzo, a now-suspended deputy UN ambassador from the Dominican Republic. Both men were accused of facilitating the bribes.

Ng's lawyer, Benjamin Brafman, said his client would be "vigorously defended."

Lawyers for the other people charged had no immediate comment or could not immediately be reached for comment.

The indictment also added two bribery counts against Sheri Yan, who had been chief executive of Global Sustainability Foundation, and had been accused of facilitating $800,000 bribes to Ashe by three unidentified Chinese businessmen.

Heidi Park, the organisation's finance director who was charged alongside Yan two weeks ago, was not named in the indictment. Prosecutors had a longer deadline to secure an indictment in her case post-arrest. Her lawyer declined comment.

Ashe, 61, continues to face only two tax-related charges. Authorities have previously said those are not covered by any diplomatic immunity he enjoys.

The defendants were expected to appear in court on the grand jury charges on Thursday, a spokeswoman for Manhattan US Attorney Preet Bharara said.

Ng was initially arrested on Sept. 19 with Yin. Prosecutors said he made false statements to customs officials about why they brought $4.5 million into the United States from China.

He has been in custody since then. A federal magistrate on Friday set his bail at $50 million and ordered him placed under house arrest. Then prosecutors, who had called Ng a flight risk, swayed the judge to delay his release until Thursday.