Authorities reportedly believe Noor Salman knew about husband's plan to attack Pulse nightclub
The wife of Orlando gunman Omar Mateen is being questioned by the FBI over claims she knew about the plot to target the city's Pulse nightclub.
An official told the Associated Press investigators believe Noor Salman was aware of her husband's plan to attack the club in advance.
According to US reports, she told authorities she tried to stop him from carrying out the massacre, which killed 49 people in the early hours of 49 people.
The woman could face criminal charges if she is found to have had prior knowledge of her husband's intentions.
Authorities are also investigating whether the American-born gunman was living a secret life as a gay man.
The FBI is looking into reports from patrons of the club who allege he was a regular at the venue and also used gay dating apps.
Jim Van Horn, 71, said he saw Mateen multiple times at the venue's bar and talked to him once.
"He was a homosexual and he was trying to pick up men," Mr Van Horn said.
"He would walk up to them and then he would maybe put his arm around them or something and maybe try to get them to dance a little bit or something."
One club regular, Ty Smith, told The Orlando Sentinel newspaper he had seen Mateen at least a dozen times.
He said: "Sometimes he would go over in the corner and sit and drink by himself.
"And other times he would get so drunk he was loud and belligerent.
"We didn't really talk to him a lot, but I remember him saying things about his dad at times," Mr Smith added.
"He told us he had a wife and child."
Some have suggested Mateen's familiarity with the club may explain why he chose Pulse, rather than other clubs closer to his home in Port St Lucie, about 130 miles (200km) south of Orlando.
Meanwhile, footage has emerged showing Omar Mateen working as a security guard in 2010, six years before he shot dead 49 people at an Orlando nightclub.
The 29-year-old is seen on duty as a guard during the clean-up operation following the Deepwater Horizon oil spill in the Gulf of Mexico.
The footage appears in the 2012 award-winning documentary The Big Fix, and shows Mateen speaking with a reporter while contracted to the security company G4S.