In the lobby at the Tribeca Grand Hotel last Tuesday, a man from Liberia opened a blue duffel bag and made an unusual business offer. The bag contained eight large bricks of white paper. The man, Calvin Swen, 42, was trying to unload them, claiming the paper was in fact $4 million in $100 bills, according to a criminal complaint filed against him.

Mr. Swen had a far-fetched explanation for why this trove of currency might appear like so many blank sheets of paper, according to the complaint.

The money had been intended as foreign aid to Sierra Leone, the explanation went. When the American government delivered aid to war-torn countries, it dyed the money white to protect the couriers from being robbed, Mr. Swen allegedly told a prospective buyer.

The person he was trying to con was an undercover agent for the Federal Bureau of Investigation. Having learned of Mr. Swen’s sales pitch, the FBI set up a sting operation that led to meetings at two hotels, one of which was identified by a law enforcement source as the Tribeca Grand.

Schemes involving white or black paper being pawned off as disguised cash are nothing new. But in this case, there was a creative twist. Mr. Swen, according to the law enforcement source, said the process to reconvert the white paper back into money, required that actual $100 bills be placed in between each bill of white paper.

“And that would turn the white ones magically into negotiable U.S. currency,” the source said of the mechanics of the alleged scheme.

It was for this reason that Mr. Swen demanded the undercover agent bring along $5 million in cash, according to the complaint. Instead the FBI arrested Mr. Swen, of Atlanta, just outside the hotel last Tuesday, and charged him with trying to sell counterfeit money.

A lawyer for Mr. Swen, Peter Antioco, did not return a call for comment yesterday. Nor did a spokeswoman for the hotel.