The premier of the British Virgin Islands was arrested on Thursday in the Miami area on drug trafficking and money laundering charges, the authorities said.

According to a criminal complaint filed in the U.S. Southern District of Florida, Andrew Fahie, who is the elected head of government of the small territory of about 30,000, requested an upfront payment of $500,000 to let cocaine slip through the territory en route to Miami and New York. He was charged with conspiracy to import at least five kilograms of a cocaine mixture and conspiracy to launder money.

The territory’s director of ports, Oleanvine Pickering Maynard, and her son Kadeem Stephan Maynard, also face those charges, according to the complaint.

A man who presented himself as working for the Sinaloa Cartel, but who was a confidential source for the federal authorities, met with Ms. Maynard on March 20, according to the complaint.

The man told Ms. Maynard he needed help ferrying thousands of kilograms of cocaine from Colombia through Tortola, which is in the British Virgin Islands, according to the document. Ms. Maynard agreed to assist, and said Mr. Fahie would also be open to such an arrangement, according to the complaint.

On April 7, the confidential source met with Mr. Fahie, who requested the upfront payment to get the process started and said that Ms. Maynard could provide the licenses needed for the cocaine to slip through the ports, according to the complaint. The source then gave Mr. Fahie $20,000 and said, “This is a good faith gift, to seal that we have an agreement,” according to the document.

The source also proposed that the authorities could organize seizures of bad drugs and money by Mr. Fahie in the territory to throw off suspicion and make it look as if he were fighting drug trafficking, the document said.

“Fahie laughed and said the CS had thought of everything,” the document said, referring to the confidential source.

Mr. Fahie, Ms. Maynard and Mr. Maynard could not immediately be reached and it was unclear who their lawyers were.

In a statement on Thursday, Anne Milgram, the administrator of the Drug Enforcement Administration, said that the arrests “should send a clear message.”

“Anyone involved with bringing dangerous drugs into the United States will be held accountable, no matter their position,” she said. “Today is yet another example of D.E.A’s resolve to hold corrupt members of government responsible for using their positions of power to provide a safe haven for drug traffickers and money launderers in exchange for their own financial and political gain.”

In an earlier statement on Thursday, Liz Truss, British foreign secretary, said she has spoken with the governor of the British Virgin Islands and that he would be holding an emergency meeting on the matter.

“I am appalled by these serious allegations,” she said. “This arrest demonstrates the importance of the recently concluded Commission of Inquiry.”

Ms. Truss was referring to an independent inquiry by the territory’s governor, John Rankin, that began in January 2021 with the goal of reviewing the territory’s governance and making recommendations for improvement.

The purpose of the continuing inquiry “is to establish whether there is evidence of corruption, abuse of office or other serious dishonesty that has taken place in public office in recent years, and if so what conditions allowed this to happen,” according to the British government.

The investigation, officials said, “has been launched, in part, in response to wide public concerns.”

Katie Benner contributed reporting.