• Former President Donald Trump's net worth was inflated by billions of dollars each year more than the New York attorney general's office originally estimated, the office alleged in a new court filing.
• Attorney General Letitia James' office found that Trump's net worth in any given year between 2011 and 2021 was overstated by $1.9 billion to $3.6 billion.
• Her sweeping fraud lawsuit alleges Trump, his adult sons and his businesses made fraudulent financial claims to obtain better loan terms and manipulate taxes for the Trump Organization.

Former President Donald Trump's net worth was inflated by billions of dollars more than what the New York attorney general's office initially found to be the case, Attorney General Letitia James said in a new court filing Friday.

Citing an extensive analysis by valuation and accounting experts, James' office found that Trump's net worth in any given year between 2011 and 2021 was overstated by $1.9 billion to $3.6 billion.

This new, larger number is "still a conservative estimate," James wrote in the Friday filing, because those experts accepted at face value many of the elements of Trump's financial statements "that would otherwise be rejected in a full-blown appraisal review."

The new claims were part of a motion in opposition to Trump's request for a summary judgment in his favor in the attorney general's sweeping civil fraud lawsuit.

Filed in September 2022, the suit alleges that the former president, his adult sons and his businesses defrauded banks and insurance companies for years in an effort to obtain better loan terms and manipulate taxes for the Trump Organization. The prosecutor is seeking $250 million in damages.

The case is set to head to trial on Oct. 2.

In another filing later Friday, New York Supreme Court Judge Arthur Engoron said the trial is scheduled to last more than 11 weeks, ending by Dec. 22. The trial will take place five days a week, starting at 10 a.m. ET each day and ending at 4:30 p.m. on all days except Fridays, when proceedings will end at 1 p.m.

Attorneys for Trump, who is running for the 2024 Republican presidential nomination and fighting nearly 100 criminal charges in four separate cases, had asked to delay the trial date, but Engoron refused.

Attorneys for Trump did not immediately respond to CNBC's request for comment on James' latest filing.

James first asked the court for partial summary judgment against Trump in the case on Aug. 30, asserting that a "mountain of undisputed evidence" backed up her allegations.

In that filing, James wrote that "numerous deceptive schemes" used to inflate Trump's total assets had a "staggering" cumulative effect, overstating his net worth by between $812 million and $2.2 billion per year.

On Friday, however, the attorney general wrote that Trump's "deception is far greater" than what was laid out in her late August filing, which relied solely on the undisputed evidence in the case.

If one were to include factors likely to be taken into account by a bank or a real estate developer that was estimating current property values, Trump's net worth is "overstated by billions more" than the August figures, she said.

Based on the new, expert analyses, James alleged that the net worth that Trump reported every year on his "Statement of Financial Condition" was inflated by $3 billion or more for seven years straight, starting in 2013.

The case is set to become Trump's first to reach trial since he left the White House.

On Wednesday, Engoron rejected Trump's bid to delay the trial until three weeks after he has ruled on competing motions for summary judgment. The judge called the request "completely without merit."

James earlier this week asked Engoron to sanction Trump and others in the case for repeatedly putting forward the same failed legal arguments. As of Friday, he had not yet responded to the motion.