A former Montana high school trainer already facing charges he sexually abused students over decades also pretended he was a teenager to meet underage boys online and abused students on trips to North Dakota and California, prosecutors said in new court documents.

The latest accusations against James Jensen were disclosed ahead of a scheduled hearing where he was expected to change his plea on charges of coercion and enticement.

On Thursday afternoon, U.S. Magistrate Judge Timothy Cavan delayed the hearing originally set for Friday until March 4 after Jensen's public defender asked for more time because of the new documents.

Jensen, 78, earlier this month requested to change his not guilty plea to guilty in U.S. District Court in Billings. But U.S. Magistrate Judge Timothy Cavan told prosecutors that he wanted a better explanation about their case against the former trainer.

Assistant U.S. attorneys Zeno Baucus and Bryan Dake filed their response Wednesday in which they described instances when Jensen crossed state lines, used the internet or otherwise engaged in interstate commerce. That's an element that must be proven in a federal case to convict a person of enticing or coercing a minor to engage in sexual activity.

Jensen's public defender, Steven Babcock, did not return a call for comment on Thursday.

Jensen was the athletic trainer for Custer County District High School in Miles City from the 1970s until 1998. Dozens of students have accused him in a lawsuit of sexually abusing them as part of what he called "The Program" that he claimed would boost their athletic performance.

In a state criminal case, he has pleaded not guilty to charges related to possessing child pornography.

The new allegations outlined by prosecutors include accusations that Jensen molested a seventh grade boy in 1995 during a trip to North Dakota for a wrestling tournament and that he abused another boy during an "athletic-related trip" to California.

The court documents also say one of Jensen's daughters confronted her father in 1995 about posing as a high school boy online to meet underage boys across the U.S. in chatrooms and dating sites. The daughter told investigators that Jensen said he was just counseling the boys.

Prosecutors further attempted to prove Jensen used interstate commerce to commit the crime by describing an interview with Jensen in which he said he obtained information about "The Program" from the internet.