The drill instructor is alleged to have ordered another Muslim recruit into an industrial clothes dryer as punishment in 2015, several months before Raheel Siddiqui died after leaping from a stairwell at Parris Island after allegedly being abused by the drill instructor.
Siddiqui had threatened suicide in the days before he died, but may not have received appropriate treatment, investigators found.
CNN and other news organizations on Wednesday reviewed hundreds of pages of redacted documents detailing three investigations into abuse allegations at Parris Island.
The drill instructor has not been identified by the Marines because the service is now considering charges against him and as many as 19 others. Some of those could be criminal charges leading to a court martial, two defense officials told CNN.
The documents detail repeated incidents -- including the one with the dryer -- such as slapping and hitting recruits, and making them do activities from stress positions, all alleged hazing.
The Muslim recruit who was put in the dryer has not been identified, but according to the documents and as first reported in The Washington Post, he suffered burns. Several Marines were subjected to ethnic or homophobic slurs, including Marines assumed to be Muslim being questioned by more senior Marines about whether they were terrorists, the documents say.
Investigation found physical and verbal abuse
Three "command-level investigations" concluded that Siddiqui committed suicide, the Marines said last week
. But Siddiqui's family has told CNN affiliate WDIV in Detroit
that they strongly doubt he killed himself.
The 20-year-old from Michigan died March 18.
The Marines recommended a number of changes, including mandatory suspension of personnel investigated for abusing or hazing recruits and increased officer oversight of training.
Last week's statement said some commanders and senior enlisted advisers were relieved of duty and some drill instructors were suspended.