Orlando nightclub killer's wife may face charges for role in massacre

The wife of a gunman who massacred 49 people at an Orlando gay nightclub could soon face charges over the attack, amid reports she "had knowledge" of his plans.

The Reuters news agency on Tuesday quoted a unnamed "law enforcement" source as saying that a federal grand jury had been convened and could charge Omar Mateen's wife, Noor Salman, as early as Wednesday.

Separately, US Senator Angus King told CNN on Tuesday evening that "it appears she had some knowledge of what was going on". 

"She definitely is, I guess you would say, a person of interest right now and appears to be cooperating and can provide us with some important information," King said.

Mateen was shot dead after killing 49 people and injuring 53 others at Orlando's Pulse club early on Sunday. He called police to claim allegiance to various groups including the Islamic State.

FoxNews.com, citing an FBI source, said prosecutors were seeking to charge Mateen's wife as an accessory to multiple murders and attempted murders, failure to notify police about the attack, and lying to federal agents.

NBC News said Salman told federal agents she tried to talk her husband out of carrying out the attack. But she also told the FBI she once drove him to the Pulse nightclub because he wanted to scope it out, the network said.

On Tuesday it was reported that Mateen, who had a professed hatred of gay people, had attended Pulse on several occasions as a customer. The reports said he had used gay dating apps.

A former wife of Mateen, Sitora Yusufiy, said her ex-husband had facets of his life that he did not share with his family, such as drinking and going to nightclubs.

"He did have a different side to him that he could not open up to his father about," Yusufiy told CNN.

She has previously said he was mentally unstable and beat her and that she fled their home after four months of marriage.

However Barbara Poma, the owner of Pulse, denied reports that Mateen had been a regular.

"Untrue and totally ridiculous," a spokeswoman for Poma told Reuters when asked about the claim.

Mateen's father, Seddique Mateen, indicated soon after the attack that his son had harboured strong anti-gay feelings and on Tuesday he said his son had never mentioned being homosexual.

"I don't believe he was a whatever you call it," he said.