The New York attorney general’s office says it is now conducting a criminal investigation into Donald Trump’s business empire after expanding what had previously been a civil probe.

“We have informed the Trump Organisation that our investigation into the company is no longer purely civil in nature,” Fabien Levy, a spokesman for attorney general Letitia James, said in a statement.

“We are now actively investigating the Trump Organisation in a criminal capacity, along with the Manhattan DA (district attorney).”

Ms James’s investigators are working with the Manhattan district attorney’s office, which has been conducting a criminal investigation into the former US president and his company, the Trump Organisation, for two years. Ms James and district attorney Cyrus Vance Jr are Democrats.

No explanation was given by Ms James’s office as to what prompted the change in its approach to the investigation or why it chose to announce it publicly.

Ms James’s disclosure of a widening investigation is not necessarily an indication that she is planning to bring criminal charges.

Her office’s civil investigation and Mr Vance’s criminal probe had overlapped in some areas, including examining whether Mr Trump or his businesses manipulated the value of assets — inflating them in some cases and minimising them in others — to gain favourable loan terms and tax benefits.

Mr Vance’s investigation also included an examination of hush-money payments paid to women on Mr Trump’s behalf, and the propriety of tax write-offs the Trump Organisation claimed on millions of dollars in consulting fees it paid, including money that went to Mr Trump’s daughter, Ivanka.

Mr Vance’s office has not publicly said what it is investigating, citing grand jury secrecy rules, but some details have emerged during a legal battle to gain access to Mr Trump’s tax records, which it finally obtained in February.

As part of her civil investigation, Mr James’s office issued subpoenas to local governments in November 2019 for records pertaining to Mr Trump’s estate north of Manhattan, Seven Springs, and a tax benefit Mr Trump received for placing land there into a conservation trust.

Ms James was also investigating similar issues relating to a Trump office building in New York City, a hotel in Chicago and a golf course near Los Angeles. Her office also won a series of court rulings forcing Mr Trump’s company and a law firm it hired to turn over troves of records.

Mr Vance’s investigation has also appeared to focus in recent weeks on the Trump Organisation’s long-time finance chief, Allen Weisselberg.

His former daughter-in-law, Jen Weisselberg, has given investigators reams of documents as they look into how some Trump employees were compensated with apartments or school tuition.

Mr Weisselberg was subpoenaed in Ms James’s civil investigation and testified twice in 2020.