Trump says New York criminal probe is in 'desperate search of a crime'

Former US President Donald Trump has attacked New York state's attorney general for launching a criminal probe of his family business, saying he was "being unfairly attacked and abused".

"There is nothing more corrupt than an investigation that is in desperate search of a crime," Trump said in a statement, adding that "we will overcome" any attempt at prosecution.

The office of New York Attorney General Letitia James, which has been investigating whether the New York City-based Trump Organization falsely reported property values to secure loans and obtain economic and tax benefits, said on Tuesday its probe was no longer purely civil.

"We are now actively investigating the Trump Organization in a criminal capacity, along with the Manhattan DA," Fabien Levy, a spokesman for James, said in a statement, using the abbreviation for "district attorney."

Trump on Wednesday assailed the investigation as politically motivated.

"The attorney general of New York literally campaigned on prosecuting Donald Trump even before she knew anything about me," the Republican former president said. James is a Democrat.

Manhattan District Attorney Cyrus Vance has been investigating Trump’s pre-presidency business dealings for more than two years.

Vance’s office has said in court filings it was investigating "possibly extensive and protracted criminal conduct" at the Trump Organization, including tax and insurance fraud and falsification of business records.

Separately, the New York Times reported late on Wednesday that the office of the New York Attorney General had been criminally investigating Allen Weisselberg, the CFO of the Trump Organization, for months over tax issues, and had notified the company about it in a January letter.

The investigators have examined whether taxes were paid on fringe benefits that Trump gave him, including cars and tens of thousands of dollars in private school tuition for at least one of Weisselberg's grandchildren, according to the newspaper.