Disturbing update as FBI investigates death of 18-year-old cheerleader on cruise ship

A family member of the 18-year-old cheerleader found dead on a Carnival cruise ship has reportedly become a suspect in the investigation into her sudden death, court documents have revealed.

Florida teen Anna Kepner died on November 7, while on a family cruise through the Caribbean with her father, step-mother and two step-siblings.

The Carnival Horizon ship was on its return journey to Miami when her body was found by staff, with ABC reporting that she was wrapped in a blanket and covered with life vests

Preliminary medical reports into the Titusville cheerleader's mysterious death indicate that she died as a result of asphyxiation, likely caused by a bar choke hold across her throat - where an assailant wraps their arm around a neck until their victim stops breathing.

While the FBI have refused to comment on its ongoing investigation, responsibility for which is being shared with local law enforcement, unrelated family court documents uncovered by CBS have shown that Kepner's family believe her 16-year-old step-brother has become a suspect in the inquiry into her death.

Anna was on vacation with her father and step-family when she died (Facebook/Shauntel Kepner)

The documents, filed on Tuesday (November 18) in Brevard County, Florida, as part of custody proceedings relating to a former marriage of step-mother Shauntel Hudson, asked for a pause in the process as she had been notified that one of her children had become involved in the investigation.

Hudson 'has been advised through discussion with FBI investigators and her attorneys, that a criminal case may be initiated against one of the minor children of this instant action,' the documents allege.

The filings claimed that Hudson was unable to provide testimony at this time due to the 'extremely sensitive and severe circumstance' surrounding Kepner's sudden death.

Further documents seen by the Brevard County court and filed a day later identifies Hudson's teenage son with the initials 'T.H.' as the child being investigated in connection with the incident.

"There is an open investigation regarding [Kepner's] death… and T.H. is a suspect regarding this death which occurred recently on a cruise ship," the filing from step-mom Hudson states.

The 18-year-old was looking forward to graduating and beginning life as an adult (Instagram/Anna Kepner)

These filings also show that the 16-year-old is currently living with another family member to ensure the safety of his other siblings, with his biological father offering to provide him with a lawyer.

Kepner, who was looking forward to her next step into adulthood as either a college cheerleader or serving the community by joining the military, had been sharing a state room on the ship with her step-brother and another step-sibling.

Her 16-year-old step-brother was allegedly allowed to drink once the Carnival ship reached international waters, according to an attorney involved in the separate court proceedings. Once the ship docked in Miami, he was taken to hospital.

Neither federal agents nor Carnival Cruise Line have confirmed the 18-year-old cheerleader's cause of death, with FBI investigators remaining tight-lipped on whether a crime has taken place and if charges will be filed.

Carnival said in a statement: “Our focus is on supporting the family of our guest and cooperating with the FBI.”