FBI offices in South Florida have received thousands of tips from members of the public since Sunday, when terror suspect Omar Mateen shot and killed 49 people at the gay club Pulse in Orlando.

Many of them have been bum tips, but some have been accurate and have helped investigators track Mateen's whereabouts before his bloody rampage.

Among members of the public trying to help is a woman in West Palm Beach, Florida, an hour south of the shooter's hometown of Fort Pierce.

She has told the Daily Mail Online that she believes she spoke with Mateen and his wife, Noor Salman, the week before the attack on the Pulse nightclub.

Lucyann Crystal believes she often saw and spoke to Omar Mateen and his wife, Noor Salman at the Pit Row bar. Crystal works as a rose peddler in West Palm Beach

Crystal says she saw Mateen and Salman (pictured together) over Saturdays nights at the bar Pit Row with a group of other 'foreigners' - four other men and two women

She says she saw Mateen and Salman over Saturdays nights at a local bar with a group of other 'foreigners' - four other men and two women.

After the identity of the shooter emerged, she was concerned enough that she called a retired police officer she knows to tell him what she saw.

The retired cop, Rick Sessa, then called the FBI to make sure agents would follow up.

'When you look into someone's eyes, you recognize a person,' said Crsyal. 'And the woman with the pretty eyes was definitely the killer's woman.'

'Her tip could mean this guy (Mateen) was part of a conspiracy,' Sessa told Daily Mail Online in an exclusive interview. 'I didn't want her words to go by the wayside, whether she's right or wrong. I think her observations are worth a check by agents.'

The witness, Lucyann Crystal, works as a late-night rose peddler. She makes her living selling single flowers in bars, restaurants and clubs.

Crystal, who lives in an apartment with her two adult sons, says her route usually takes her to Pit Row, a dark neighborhood bar in Palm Springs, near West Palm Beach, with three pool tables.

'I go in there about 11pm most Saturdays,' Crystal tells the Daily Mail Online.

A former nursing student, she was forced to cut her studies short when she was attacked savagely by her ex-husband who nearly stabbed her to death in front of their two boys.

She recovered, but she partly lost control of the left side of her body and started working menial jobs to feed the boys.

'About six months ago, I started making it a habit of talking to a group of foreign people that I saw playing pool in the back once a month or so,' she continued. 'They're always the same five men and three women. They're playing and having fun and they always have wisecracks for me.'

Crystal now says one of the women in the group was Noor Salman.

She says: 'There's not a single doubt in my mind. I struck a friendship with her because she'd always defend me when the men got rude to me. I commented about her pretty eyes and I talked to her every time I saw them.

'I spoke to her four or five times over the past six months. I am 100 per cent sure. That was the wife of the terrorist I see on TV every night.'

Mateen, Crystal says, was among the five men but wasn't as talkative as the woman.

'I thought they were Mexicans or something, but I'm bad with languages.'

She saw the group for the last time on the night of June 4, Crystal says. That night, the man she believes was Mateen made a strange statement to her.

She says: 'Someone in the group called me over with the roses. I knew they weren't going to buy but they always talked politics. About Trump and stuff like that. One of them asks me how I feel about the transgender bathroom controversy.

'So I said, "Doesn't matter to me where they pee, but I know God won't let them [transgendered people] into heaven".

'So they all started laughing like it was the funniest thing they heard all night.

Crystal is a rose peddler, who says her route usually takes her to Pit Row, a dark neighborhood bar in Palm Springs, near West Palm Beach, with three pool tables

She said she saw Mateen, Noor and others at the local bar (pictured inside), and would often chat with them after befriending Noor because of her 'pretty eyes'

After the identity of the shooter emerged, she was concerned enough that she called retired police officer Rick Sessa to tell him what she saw. Sessa then called the FBI to make sure agents would follow up

'But the guy on the TV who's the shooter, and I recognized his glasses, says to me: "Do you realize that comment just saved your life?"

'I must've looked startled because the woman who was with him grabbed my arm and told me he didn't mean anything by it. She even talked him into buying a red rose. He gave me $5 and I left.'

Crystal replayed the incident in her head several times that weekend because she couldn't make sense of Mateen's words, Crystal said.

'When I first saw him on TV Sunday, he looked familiar,' Crystal said. 'When I first saw her Tuesday, I knew it was them.'

A grand jury is considering criminal charges against Noor.

Meanwhile, a manager at Pit Row, the bar, said the business' surveillance video automatically erases images captured seven days earlier.

And a check of credit card receipts for the establishment was inconclusive and couldn't confirm the killer's presence there in the past six months.

Still, says Crystal, not all customers use credit cards.