Federal authorities may be investigating the stepsibling of the Florida high school cheerleader whose lifeless body was found wrapped in a blanket and stuffed under a bed on a Carnival cruise ship, a shocking new court filing revealed.

The potential federal probe comes nearly two weeks after Anna Kepner, 18, was discovered dead in her cabin on Nov. 7 during a six-day Caribbean cruise with her family aboard the Carnival Horizon.

In an emergency motion first obtained by The Daily Mail that was filed Monday in Brevard County, Kepner’s stepmom, Shauntel Hudson, requested extra time to respond to filings tied to her 2024 divorce from her ex-husband, citing an “extremely sensitive and severe circumstance.”

“Currently there is an investigation being conducted by the Federal Bureau of Investigations (F.B.I.) arising out of the sudden death of eighteen-year-old Anna Kepner,” the filing states, noting that Hudson and her children were all on the cruise with the teen and her father, Christopher, when she was found dead.

“The respondent has been advised through discussions with the FBI investigators and her attorneys, that a criminal case may be initiated against one of the minor children of this instant action,” the filing continued, according to ABC News.

Hudson, a mother of three who recently married Kepner’s father, asked that the proceedings be postponed until the “criminal investigation has concluded,” cautioning that her testimony could be “prejudicial” to both her and her “adolescent” child while the probe continues.

Hudson could not be reached for comment.

The FBI and her ex-husband did not immediately respond to The Post’s request for comment.

Kepner — affectionately nicknamed “Anna Banana” by her family — was wrapped in a blanket, covered in life jackets, and shoved underneath a bed when she was found dead, sources told the Daily Mail.

The gymnast and cheerleader, who was set to graduate from Temple Christian School in Titusville in May, had told family members at dinner the night before that she was not feeling well and went back to her room, the sources said.

But the next morning, she was nowhere to be found when her family gathered for breakfast.

A desperate search swept the massive ship, which can carry nearly 4,000 passengers, until a maid stumbled upon Kepner’s body in her cabin around 11 a.m., prompting the ship to abruptly change course for the Port of Miami, Florida.

The Miami-Dade County medical examiner lists her time of death as 11:17 a.m. Nov. 7, but does not say how she died.

“I have no idea what is going on right now,” her grieving father, Christopher Kepner, told the outlet last week, adding that the heartbroken family is still in the dark over what happened.

“We are just trying to sit still and wait for answers.”

The FBI is handling the investigation since the bubbly teen died in international waters, but officials have offered frustratingly few details about how she died.