Mark says three days after he met “Kelly Smith” on an online dating site, she told him she had a multi-million dollar inheritance in Nigeria, and she needed help getting it to the United States.

“Her father left her [the] deed to property in Nigeria worth about $3.5 million and goods worth $2 or $3 million,” Mark says. “She told me she had the money and goods put in two steel boxes.”

WATCH: Man Who Has Sent $750,000 To Help Woman He Met Online Learns Truth About Email Exchanges

Mark says he’s spent more than $750,000 to help “Kelly” get the boxes shipped from Nigeria to the U.S. He says he has been working with a professional shipper that “Kelly” hired to get the correct documents and stickers, and to pay custom fees around the globe, to have the boxes transferred to his name and to land in America.

WATCH: Why Man’s Overseas Online ‘Girlfriend’ Said She Didn’t Want Him To Appear On "Dr. Phil"

It’s been six years and Mark has still not received the boxes – but he says he’s certain he is not being scammed.

The Dr. Phil show conducted an international investigation to determine where the boxes are. In the video above, see what is discovered at the address that Mark gave for “Kelly” in Nigeria. And, is the reporter able to locate the shipper and the boxes? This episode of Dr. Phil airs Tuesday. Check here to see where you can watch.