U.S. prosecutors say they have dropped drug-related charges against 27 south Florida defendants, although they declined to say why.

The cases involved South Florida head shops that reportedly sold undercover agents compounds used to "cut" cocaine, then sent the profits to the Middle East for possible terrorist activities, the Miami Herald reported Saturday.

The U.S. attorney's office issued a statement saying, "new information surfaced that, in our discretion, made it appropriate to dismiss the charges."

"At this time, I cannot provide further details of what that information entailed, as it is not in the public record," said Alicia Valle, special counsel to the U.S. attorney.

Dropping charges against all the defendants in such a case is very unusual, said a former government drug agent.

"Dropping charges against a few defendants is not that unusual," said attorney David Weinstein, former chief of the narcotics and national security sections at the U.S. attorney's office in Miami. "Dropping charges against 27 defendants connected together in one investigation is highly unusual."

The two-year investigation, called "Operation Cedar Sweep," focused on head shop owners in south Florida. Most of the owners were of Lebanese descent. Prosecutors were unable to make a connection between the shop owners and terrorist organizations.

The defendants were accused of selling compounds containing regulated pharmaceutical products, including lidocaine, tetracocaine or benzocaine.

An attorney for one of the defendants said the case was flawed because the defendants didn't break any law.

"They sold legal products that you can find at a GNC," said Miami attorney Joseph Rosenbaum, who represented defendants Khaled Nabil Ismail and Mohamad Ali Jawad. "No drugs were ever found on the premises. No crime was ever committed."