Prosecutors said she “had not signed or authorized the letter” to her agent and “did not even know of its existence.” Mr. Avenatti tried to conceal the effort by advancing money to her “from another source” to stand in for one installment, prosecutors said, and he falsely said the publisher had not paid when she asked about another portion.

Mr. Avenatti drew national attention when he began representing Ms. Daniels in early 2018, filing lawsuits against President Trump and Michael D. Cohen, the president’s former lawyer and fixer. He sought to release Ms. Daniels, whose legal name is Stephanie Clifford, from a hush agreement she had signed before the 2016 election. As part of that deal, she accepted $130,000 and agreed to keep quiet about a sexual relationship she said she had had with Mr. Trump in 2006.

Both of the lawsuits Mr. Avenatti filed on behalf of Ms. Daniels were dismissed, and in one case she was ordered to pay Mr. Trump $293,000 in legal fees.

Yet Ms. Daniels’s story created further trouble for the president, culminating in Mr. Cohen’s guilty plea last year to campaign finance crimes related to the hush payment. This month, he began serving a three-year prison sentence. The same office that won Mr. Cohen’s guilty plea — the public corruption unit of the United States Attorney’s Office for the Southern District of New York — filed the new charges against Mr. Avenatti, which included aggravated identity theft.

The new charges add to numerous others filed this year. Mr. Avenatti was arrested in New York in March on extortion charges, accused of seeking millions from Nike in exchange for what he described as evidence of misconduct by company employees in the recruitment of college basketball players. On Wednesday, he was also indicted on those previously announced charges.

In a separate indictment filed in California this spring, Mr. Avenatti was accused of stealing millions of dollars from five other clients, one of them a paraplegic man who had won a $4 million settlement but received only a fraction of that in periodic payments that never exceeded $1,900. Mr. Avenatti was also accused of filing fake tax returns to a Mississippi bank, and of lying repeatedly about his business and income to an agent of the Internal Revenue Service, creditors, a bankruptcy court and a bankruptcy trustee.

Mr. Avenatti, who spent much of 2018 crusading against Mr. Trump on cable news shows and teasing a presidential run of his own, has called the cases against him politically motivated.