For four months, from last November through February, Fairfax County attorney Spiros Anthony has as his client one of the most celebrated figures in America - heavy-weight boxing champion Muhammad Ali.

In a flurry of financial activity, Anthony bought for his client a $1.8-million office building in Springfield area and 24 condominiums in Herndon that had gone into foreclosure.

The relationship ended abruptly March 1 when Ali fired Anthony as his financial trustee. The boxing champion later in the month sued Anthony for $2 million, claiming he "breached his . . . duties" as trustee of the money, part of Ali's $6.1-million gross from his victorious New York bout with Ken Norton last September.

In the suit, filed in U.S. District Court in Alexandria, Ali charged that Anthony misused money put into escrow for taxes by spending, among other sums, $45,250 to purchase for his own use rare Services (French) procelain and other expensive antiques at Thieves Market in Alexandria. A trustee is a person who accepts responsibility for handling the money or property of another person.

Anthony has charged in a counter suit that Ali owes him $3 million in profits from various "joint ventures" involving the two of them. According to court papers filed by Anthony, the ventures included the retailing of packaged chicken called Champ Chicken and the selling of Mack trucks and prayer rugs in Middle Eastern countries.

The lawyer denied in court papers he had misused any money put aside for Ali's last tax bill, estimated at about $2 million and due last Jan. 15.

Precisely how much, if any, of Ali's money has been irretrievably lost is unclear. "we don't know," said one of Ali's many legal advisers.

Ali's attorney in the suit, former Fairfax County supervisor Harold O. Miller, said that only about $80,000 of the escrow money can be accounted for in two bank accounts.

Though Ali's suit was filed last month, all the documents were sealed until yesterday by Judge Albert V. Bryan Jr. in Alexandria at the request of attorneys for both Ali and Anthony.

The papers cast some revealing light on the financial affairs of Ali, who, according to one letter from the Internal Revenue Service, made $12.8 million in 1976. His expenses were put at $8 million.

Though expenses cut his income by more than 70 per cent Ali still had enough left - $4.8 million - to be in the maximum 50 per cent tax bracket.

Anthony paid $400,000 to the IRS on Ali's behalf, but two checks toward the balance of his client's $2.4 million tax bills were returned by a bank because of insufficient funds, Ali claims. Anthony, in court papers, said the checks were returned because Ali stopped payment on them.

Repeated attempts to reach Anthony for comment were unsucessful.

Ali appointed Anthony, a Howard University law graduate who practices in a suite in Skyline Tower at Baileys Crossroads, as his trustee last November.

According to Miller, Ali placed "in excess of $2 million" in the escrow account for which Anthony was trustee.

According to Anthony's lawyers, Louis Koutoulakos of Arlington and Nelson Deckelbaum of Washington, only $230,000 was placed in the escrow account. Unspecified "additional funds," Anthony's lawyers said in court papers, "were not pursuant to the escrow account."

Anthony replaced a Philadelphia firm as trustee of Ali's escrow account, maintained so that the champion would have enough money to pay his federal tax bills when they came due. Why Ali chose the Fairfax lawyer is not clear.

In his countersuit Anthony said that as early as November, 1975, "Ali became aware of the attorney's extensive knowledge . . . and business acumen" and asked him to "explore the possibility of capitalizing upon the worldwide image of Ali and to present to Ali a proposal which would encompass long-range financial planning and tax savings."

As part of Anthony's investment plan for Ali, the Fairfax attorney bought the Springfield office building from former Fairfax board chairman Prederick A. Babson and the 24 Herndon condominiums in the Jefferson Mews project from Virginia National Bank.

Real estate is a favorite investment of people like Ali who are in high-income tax brackets. It is called a tax shelter because it can be depreciated over a number of years even though, it may earn income and actually increase in value, based on rising assessments.

Ali claimed in court papers that part of the money that was supposed to be set aside for taxes was spent on real estate ventures in violation of the escrow agreement.

Under the agreement, the money Ali gave Anthony could be invested "in a prudent manner."

According to Miller, Ali's attorney, a prudent investment in this case would have mean Treasury notes or certificates of deposit at banks.