NEW YORK (AP) — The trial of a former Goldman Sachs banker accused in a massive international swindle has hit a snag with prosecutors' admission that emails and other documents were mistakenly withheld from defense.

The fraud case against Roger Ng went forward in federal court in Brooklyn on Thursday with the fourth day of testimony by the government's star witness, Tim Leissner. But a judge has said that once the direct examination of Leissner is over, she will pause the trial for as long as it takes for the defense to review the newly disclosed evidence before it does its cross-examination.

In a filing on Wednesday, prosecutors blamed the failure to turn over 15,500 documents on a legal team in Washington assigned to identify material that the defense had a right to see before the trial started. They called it an "error" that was "inexcusable," but argued the trial should move ahead.

A message was left Thursday with Ng's lead attorney seeking comment.

Leissner, another former Goldman banker, has testified as part of a plea deal that he and Ng agreed to take tens of millions of dollars in kickbacks as compensation for their roles in a $4.5 billion scheme to loot a Malaysian state investment fund known as 1MDB.

The defense contends prosecutors are making Ng a scapegoat for "corporate-wide" failures at Goldman that enabled the colossal fraud orchestrated by superiors like Leissner.