A onetime real estate baron, Adam Hochfelder, whose holdings included the Helmsley Building, is facing charges that he forged a business partner’s signature and lied in applying for loans during the height of his success.

In less than eight years, Mr. Hochfelder, who is now 37, amassed a real estate portfolio that is reported to have held as much as 7 million to 8 million square feet. His ascent in the world of Manhattan real estate began in earnest more than a decade ago, when he teamed up with developer Richard Kalikow to begin buying buildings. Their company, Max Capital Management Corp., received backing from billionaire Robert Bass.

Mr. Hochfelder’s partnership with Mr. Kalikow, like the successive ones that defined Mr. Hochfelder’s brief career, has not endured. Mr. Kalikow ended up suing Mr. Hochfelder.

“He came in with me and I was experienced and he did well with me,” Mr. Kalikow said of his former business partner. “And then he went on his own and obviously he didn’t do well on his own.”

Mr. Hochfelder was arrested yesterday afternoon at his home on East 96th Street, his lawyer, Paul Goldberger, said. The Manhattan district attorney’s case against Mr. Hochfelder, it appears, began under unusual circumstances, with Mr. Hochfelder seeking out prosecutors, not the other way around.

“We walked on in, on our own, four years ago, because it was time to,” Mr. Goldberger said. “Truthfully, it was Adam’s conscience. Some of the things that had taken placed needed to be disclosed.”

Mr. Goldberger declined to say what it was that Mr. Hochfelder sought to disclose to the district attorney’s office. But he said that he and Mr. Hochfelder have been talking with prosecutors on a “weekly basis” since then.

At a news conference yesterday, the district attorney, Robert Morgenthau, said Mr. Hochfelder is charged with grand larceny and forgery relating to a series of loans he took from banks, business partners, and family and friends.

The loans started in 2002 and total some $17 million, about $12 million of which Mr. Hochfelder has paid back, Mr. Morgenthau said. In seeking $10 million in personal loans from North Fork Bank and Bank of America, Mr. Hochfelder provided forged documents claiming he held a stake “in property he never owned or in which he had little to no interest at all,” Mr. Morgenthau said.

Mr. Hochfelder also forged the signature of a business partner, Anthony Westreich, in order to use Max Capital’s income as collateral against Mr. Hochfelder’s personal loans, the district attorney alleged.

At one point, Mr. Hochfelder also lied in an official document about how many liens were on a home he has since sold, a $4 million apartment at Park Avenue and 83rd Street, Mr. Morgenthau said. About a year ago the co-op board asked him to leave, a source with knowledge of the matter said.

“When he took money from somebody else illegally, he used the money that he took to pay off the earlier loans,” Mr. Morgenthau said. “To steal money and then a couple years later say, ‘I’m sorry, I’ll pay it back,’ is still a theft.”

Today, Mr. Hochfelder owns no buildings in Manhattan, his lawyer said. After buying out Mr. Kalikow’s share in their company in 2002, Mr. Hochfelder was himself bought out by Mr. Westreich two years later. Mr. Westreich rebranded the company as Monday Properties, suggesting a new beginning. Most recently, Mr. Hochfelder briefly had a stake in a hotel in Aruba, and was seeking to buy a resort in Telluride, Colo., the New York Times reported in April.

“He’s an exceptionally charming guy and he had a great ability to raise money from anybody,” Mr. Kalikow explained of Mr. Hochfelder earlier successes.

A 2003 profile in the New York Observer reported that Max Capital’s holdings also included 450 W. 33rd St., whose tenants include the Daily News and the Associated Press, as well as the former Condé Naste building at 350 Madison Ave.

In 2003, Mayor Bloomberg appointed Mr. Hochfelder to a city commission on Latin Media and Entertainment.

Mr. Hochfelder has not yet been arraigned, but that is expected to happen today in state Supreme Court in Manhattan. Mr. Goldberger declined to comment on any of Mr. Morgenthau’s allegations, saying he would not comment until he had seen the indictment. A copy of the indictment was not yet available yesterday.