Police continue to investigate the cause of death a 51-year-old Florida mother found Sunday in the Atlantic Ocean, though her family already suspects foul play.

The medical examiner ruled that Josephine Frenna drowned without any signs of a struggle, according to the Miami Herald. But detectives said they weren't ruling anything out yet, and those close to her worry that something sinister happened, pointing to the fact that she didn't like to swim.

"Josephine wasn't a water person," family friend Steve Stabile told the Herald. "She wasn't one to go swimming on the beach. She hated the sand. She wouldn't even put a toe in the swimming pool.'"

Ft. Lauderdale police say they're investigating any and all possibilities.

''We're still looking at leads,'' department spokesman Sgt. Frank Sousa told the Herald. "We understand the family has questions. Hopefully, we'll be able to provide them with some answers.''

Frenna disappeared Thursday, the day before a court hearing on a restraining order against her estranged husband, whom she described as violent and dangerous in court documents.

She was last seen after taking her 14-year-old son on foot to a bus stop near their condominium. All her personal belongings, including her keys, wallet and credit cards, were still inside, and her car was parked out front.

Detectives searched for Frenna for days. On Sunday, the U.S. Coast Guard found a woman's body floating in the ocean. Investigators identified the dead woman as Frenna on Tuesday through dental records.

Police have questioned Frenna's husband, Gerardo Di Marco. They say he has been cooperative, and he has not been identified as a suspect in his wife's death.

Click here to read more on this story from The Miami Herald.