WASHINGTON (AP) — The Supreme Court on Monday made it tougher for the government to recover ill-gotten gains from people convicted of securities fraud, ruling that such recoveries are subject to a five-year statute of limitations.

The unanimous ruling could hamstring prosecutors trying to recoup huge sums of money in cases where alleged fraud has been going on for decades before authorities file charges.

The justices overturned a lower court decision that ordered venture capitalist Charles Kokesh to pay the Securities and Exchange Commission $35 million from investor funds he used to pay himself and others at his New Mexico-based operation from 1995 to 2006.

Lawyers for Kokesh had argued that the five-year window would reduce his payment to just $5 million because the SEC did not bring charges against him until 2009.

Justice Sonia Sotomayor said in her opinion that so-called "disgorgement" actions are the equivalent of penalties, which have long been considered subject to the five-year limit for collection.

"Disgorgement orders go beyond compensation, are intended to punish, and label defendants wrongdoers as a consequence of violating public laws," Sotomayor said.

Government lawyers had argued that disgorgement was not a punishment because the goal is to prevent those who break the law from being unjustly enriched. But Sotomayor disagreed, saying disgorgement can sometimes exceed the profits gained. She said it could include benefits to third parties or fail to consider expenses that reduce the amount of illegal profits.

Business and securities industry groups had argued that ruling in favor of the government would harm financial markets by creating uncertainty about the limits of potential liability for securities fraud. They said going beyond the five-year window would mean relying on stale evidence and witnesses with faded memories.

SEC spokesman Ryan White declined to comment on the ruling. The agency collected more than $4 billion in disgorgement actions and other penalties in the 2016 fiscal year.