For the last 10 years, Ghana had two US embassies. One is an imposing, high-security building, surrounded by wide lawns and palm trees. The other was a small office building covered in peeling paint.

And while both of them issued documents meant to grant permission to travel to the United States, only the first did so legally and with the approval of Washington, DC.

The other "embassy" was an elaborate scam, run to exploit people from across West Africa hoping to travel to the States. People would be lured to the fake embassy and charged for travel documents.

The false embassy appears to have been a complex operation. Every effort was made to convince travelers that they were in a genuine US government building. The office was staffed with white people as well as black Ghanaians and flew the stars and stripes during office hours. A portrait of Barack Obama was hung on one of the walls, and visitors were seen by appointment only.

There was little effort to keep the scam a secret. According to the US State Department, its services were publicly advertised in Ghana, Ivory Coast and Togo.

"For about a decade it operated unhindered," the State Department wrote. "The criminals running the operation were able to pay off corrupt officials to look the other way, as well as obtain legitimate blank documents to be doctored."

The BBC's Sammy Darko says the criminals involved targeted poorer and less educated people whom they thought would be less likely to see through the deception.

"They drove to remote parts of West Africa to find customers," Darko says. "They would shuttle the customers to [Ghana's capital] Accra, and rent them a room at a hotel nearby."

When police finally raided the false embassy, they found 150 passports from 10 countries. Each fake visa issued is believed to have cost around $6,000.

Since the story was made public, some arrests have been made and some alleged members of the gang have gone on the run. Nevertheless, questions remain about how the scheme was able to operate undetected for so long.

From PRI's The World ©2016 PRI