The husband of an American woman who disappeared during a boat trip in the Bahamas earlier this month has returned to the U.S. after his release from police custody on Monday evening.

Brian Hooker, 59, has maintained that his wife Lynette Hooker, 55, fell into the ocean during what was meant to be a short ride in the Abaco Islands of the Bahamas. He was arrested on April 8 in connection with her disappearance and held for five days. The U.S. Coast Guard has also reportedly opened a criminal investigation into the case.

"Mr. Hooker categorically and unequivocally denies any wrongdoing,” his lawyer, Terrel Butler, said in a statement following his arrest.

The Royal Bahamas Police Force made the decision to release him after government prosecutors recommended against filing any charges at this time, according to a statement issued on Monday.

Butler emphasized that Lynette Hooker has still not been found.

“So far, there is no evidence that she is dead,” she said. “That is an important element that they would have to prove in any charge of murder.”

In a brief interview with CBS News on Tuesday, Brian Hooker said he is maintaining hope that his wife is still alive and “won't be able to stop looking” for her.

On Wednesday, Butler said that Brian Hooker had left the Bahamas to be with his mother, who she said was very ill.

“In addition to the trauma of his wife of 25 years being missing, Mr. Hooker has received urgent word of his mother’s grave illness,” Butler said in a statement. “He has traveled to [the] United States of America to be at her bedside during this critical time.”

Here’s what we know about Lynette Hooker’s disappearance and the developments that led her husband to be treated as a suspect.

Michigan natives Brian and Lynette Hooker, avid sailors who chronicled their travels on social media, departed from the small village of Hope Town at around 7:30 p.m. local time on April 4 in an 8-foot dinghy, according to Bahamian police. Brian Hooker told authorities that his wife fell overboard along with the boat’s keys, which caused the boat’s engine to turn off.

“Strong currents subsequently carried her away, and he lost sight of her,” authorities initially reported the following day.

Brian Hooker told authorities he then paddled the dinghy for several hours before arriving at a boat yard on a separate island, where he reported Lynette Hooker’s disappearance. Local authorities mounted a widespread search and rescue effort. After days of searching without finding her, the effort shifted from an active search to a recovery mission.

In a message posted to Facebook last week, Brian Hooker wrote that he was “heartbroken” over his wife’s disappearance.

“Despite desperate attempts to reach her, the winds and currents drove us further apart,” he wrote. “We continue to search for her and that is my sole focus.”

The Royal Bahamas Police Force initially said that Brian Hooker was “being questioned” in connection with the incident, but a police official later confirmed to Reuters that he is considered a suspect.

Police haven’t discussed any potential evidence that led them to consider Brian Hooker as a suspect, but two members of Lynette’s family have publicly expressed doubts about his account of the incident.

Lynette Hooker’s daughter, Karli Aylesworth, told NBC News three days after her disappearance that it was unlikely for her mother, an experienced mariner, to “just fall” into the water.

She said that the couple had a “history of not getting along, especially when they drink.” In an interview with a local NBC affiliate, Aylesworth said her mother and stepfather had been married for 25 years, but described their relationship as “rocky at best.”

Lynette Hooker was reportedly taken into custody in 2015 on suspicion of assault and battery following an incident in which she and her husband accused each other of assault. Neither of them was charged with a crime.

Aylesworth also said that Brian Hooker sounded “monotone and relaxed” during a voicemail that he left her on Sunday, in which he told her that authorities had located a floatation device he had thrown to Lynette before her disappearance.

In the statement following Brian Hooker’s arrest, his lawyer specifically denied “the allegations recently made by Karli Aylesworth” and said Brian “has been cooperating with the relevant authorities as part of an ongoing investigation.”

Lynette Hooker’s mother, Darlene Hamlett, told the Associated Press last week that she was “glad to hear” about Brian Hooker’s arrest, but declined to comment any further on the case.

Hamlett echoed Aylesworth’s comments about her mother’s experience on the sea.

“Our family grew up on water and so Lynette her whole life has been near lakes, on boats, sailing and swimming,” she said. “It would be a miracle if [she’s rescued], but I’m still counting on one.”