Gov. David A. Paterson spent nearly $900,000 from his campaign fund in the past four months defending himself as he faced three investigations into his conduct and that of his administration.

Mr. Paterson began the year with more than $3 million in his campaign account, but he ended the period with about $615,000. In the first two months of the year, he was spending heavily as he geared up for a primary against Attorney General Andrew M. Cuomo; after dropping out of the race, he further depleted his coffers by spending aggressively on lawyers and a crisis communications team.

The spending report released Friday comes amid a sign that at least some of the investigations might be drawing closer to a conclusion.

Mr. Paterson, a Democrat, himself was interviewed in recent weeks by investigators conducting two inquiries led by a former chief judge, Judith S. Kaye, according to people briefed on the matter who would speak only on condition of anonymity because the investigations are continuing. The governor was seen as the last key witness who had not been called to testify.

In March, Mr. Cuomo named Ms. Kaye an independent counsel; the inquiries under her purview are unrelated. One involves accusations that the Paterson administration and the State Police pressured a former companion of a top aide to withdraw a domestic violence complaint. The other involves an accusation referred by state ethics regulators that the governor perjured himself when he testified this year about his receiving more than $2,000 worth of free Yankees tickets during the World Series in 2009.

Separately, the Paterson administration’s handling of a casino contract at the Aqueduct racetrack in Queens is also being investigated by state and federal authorities.

The three investigations have kept Mr. Paterson’s lawyers busy. He is represented by the Manhattan firm Paul, Weiss, Rifkind, Wharton & Garrison, which also represented his predecessor, Eliot Spitzer, when Governor Spitzer was embroiled in a prostitution scandal.

Mr. Paterson’s chief lawyer is Theodore V. Wells Jr., whose clients have included I. Lewis Libby Jr., the former aide to Vice President Dick Cheney who was tried in a high-profile C.I.A. leak case, and the former labor secretary Raymond J. Donovan, who was acquitted on fraud charges in the Bronx in the 1980s.

The governor’s team at Paul, Weiss also includes at least one other partner, Mark F. Pomerantz, a former federal prosecutor that Bank of America hired last year to assist in litigation with the Securities and Exchange Commission. Mr. Paterson has also hired Sard Verbinnen, a public relations firm, to manage news media requests and his public image in the wake of the investigations. Sard was also used by Mr. Spitzer, at the recommendation of his legal team. The Paterson campaign, according to its filing, paid Sard about $166,000.

A spokeswoman for Sard declined on Friday to comment on the case or the spending.

Mr. Paterson suspended his campaign for a full term after the domestic violence scandal emerged in March, and he has since focused his campaign resources on his legal struggles. There is precedent in New York for public officials spending campaign money on legal fees, but the pace at which Mr. Paterson is spending on legal fees is considerable.

Joseph L. Bruno, a former State Senate majority leader who was convicted in December on federal corruption charges, spent nearly $1.2 million last year from his campaign account on various legal fees and expenses, most of it going to McDermott, Will & Emery, a Washington firm where Mr. Bruno’s chief lawyer, Abbe D. Lowell, is a partner.

But the governor is spending at a much faster clip, having paid $700,000 to Paul, Weiss over four months. While Mr. Paterson is facing three investigations to Mr. Bruno’s one, the governor hired Paul, Weiss only in early March. And Mr. Bruno’s legal team had to prepare and defend its client at a federal trial last year.

A top Manhattan law firm like Paul, Weiss typically charges $750 to $1,000 per hour for work involving investigations into white-collar crimes, according to Legalbill, a legal consulting company based in Nashville that tracks legal fees. That means Mr. Paterson has been billed about 700 to 930 hours.

The governor’s campaign, which stopped raising money after he ended his bid, also returned money to some donors who had given above the maximum $37,800 allowed per person in a general election campaign, since it was designated for a primary that never took place.

Mr. Paterson’s latest campaign finance filing indicates that he was raising money at a far slower pace than he suggested publicly in the final days of his campaign. During a television interview in late February, he said he had raised about $1.5 million over the previous month, but his filing shows he raised $100,000 in the first half of the year.

Mr. Paterson has insisted he had done nothing wrong in the various inquiries, though his personal conduct has been called into question in all of them, including the perjury accusation in the Yankees ticket matter and revelations that he was courting the political support of a prominent Queens pastor, the Rev. Floyd H. Flake, who was an investor in an Aqueduct bidding group.

The domestic-violence-related case was set into motion by a report in The New York Times about an alleged assault last Halloween by a top aide to the governor, David W. Johnson, against his then-companion, Sherr-una Booker, at her apartment in the Bronx.

Both the State Police and the governor spoke with Ms. Booker while she was seeking court protection. In court, she complained that she had felt pressured by the State Police to drop the case — the matter was under New York Police Department jurisdiction — but was adamant that she would not.

The case was ultimately dismissed without prejudice when Ms. Booker did not show up for a February court date. Mr. Paterson has conceded he spoke with her the day before the court date but has insisted he did nothing to intervene in the case.

The Times reported in June that Mr. Johnson, who is also involved in the Yankee tickets matter, has invoked his Fifth Amendment right not to incriminate himself, refusing to answer questions in the investigation. He remains suspended without pay.