As the multibillion-dollar scheme led by Tom Petters approaches its sixth anniversary, the meter is still running for the lawyers and accountants sorting through the corporate empire created by the former Wayzata businessman, and the array of creditors and investors who did business with him.

More than $83 million has been paid to the lawyers and accountants working on the Petters bankruptcy after a federal bankruptcy judge last week approved $3.5 million for another stretch of legal work.

So far, trustee Doug Kelley and a team of lawyers and accountants have recovered nearly $400 million in various legal proceedings, including funds from the sale of Sun Country Airlines and Polaroid, both of which were owned by Petters.

The recovery ratio to date is $5 recovered for every $1 spent on professional fees. By comparison, in the bankruptcy of convicted New York Ponzi schemer Bernard Madoff, the recovery ratio is approximately 10 to 1 ­— legal fees totaling $927 million on recoveries reaching $9.8 billion.

Kelley predicts that the recovery percentage for Petters will improve significantly in the coming year, as approximately 75 lawsuits seeking millions in so-called false profits, also known as clawback cases, move toward trial.

“It’s taken a lot of front-end legal and accounting work to get to this stage,” Kelley said. “The percentage will look a lot better as we make more recoveries.”

Several of the clawback lawsuits being pursued by the trustee have claims in excess of $100 million each, Kelley said. Total clawback claims including principal and interest are in the neighborhood of $1.7 billion.

PricewaterhouseCoopers — the accounting firm retained by Kelley — is pursuing a detailed analysis of money in and money out for each entity and each person in the claims, Kelley said.

“That’s very labor intensive, accounting wise,” he said.

The legal theory behind the clawback litigation is that profits collected by investors were not real profits but represented funds paid to Petters by other investors. Those are known as false profits. And if the investor “knew or should have known” that the whole operation was a charade, then, Kelley said, the bankruptcy estate is entitled to the principal, or initial investment, too.

Kelley’s theory had been hotly contested for about four years by nearly 200 separate Petters investors. But through several rulings, U.S. Bankruptcy Court Judge Gregory Kishel has put in motion a process that will put that theory to the test. The process could lead to settlements, trials or dismissal.

Under the current timetable for pretrial discovery and various motions, hearings on the remaining 75 cases would start in the spring of 2015.

Since the fraud was first revealed in September 2008, 13 people have been convicted on criminal charges related to the Ponzi scheme, including Petters, who is serving a 50-year sentence in a federal prison in Leavenworth, Kan.

The ruse included the creation of false documents to make it appear that investors were financing the purchase and sale of consumer electronic goods to big-box retailers at a profit. But there were no goods and no actual transactions as Petters and his partners used funds from one group of investors to pay other investors.

While the legal community knows bankruptcy proceedings can be long and costly before investors and creditors see any of their money, the Petters case has carried a particularly high profile. It is widely believed to be the largest financial fraud case ($3.65 billion) in Minnesota history.

“There is wide awareness of this bankruptcy proceeding both for its legal and practical implications,” said Ann Graham, director of Hamline University’s Business Law Institute. “But it seems like a never-ending saga.”

Graham said it’s up to Kelley and the creditors committee to continually do cost-benefit analysis of the attempts to recover funds in the bankruptcy. “I’m sure that’s in the back of his mind,” she said of Kelley.

The creditors committee recently gave Kelley a vote of confidence when it approved the launch of an international clawback overture in an attempt to recoup any false profits paid to foreign investors. David Runck, an attorney for the creditors committee, said the group would remain “mindful of the legal costs” as Kelley proceeds.

The most recent applications for legal reimbursement contained a smattering of fees from three of the eight international law firms recently retained to pursue so-called phantom profits in overseas jurisdictions. That amount is sure to grow. International attorneys retained by the bankruptcy trustee are charging rates ranging from $450 to $600 an hour.

“My concern is that the international cases could be a big source of [additional] legal and professional fees,” Graham said. “Even though Kelley has gotten favorable rulings from Kishel [in the U.S.], there is no guarantee that he will prevail internationally.”