Fentanyl supply chain spans China, Mexico, US -- and Japan

The names on the documents mean nothing to most people. But they are deadly serious.

All are chemicals used to make the synthetic opioid fentanyl.

In July 2023, Nikkei filed information disclosure requests with Mexico's defense ministry, navy, national guard, federal prosecutor's office, public security ministry, and customs agency.

The goal of the investigation was to trace the paths of drug precursors from China to Mexico to the U.S. America's crisis of fentanyl addiction has put more stress on the U.S.-China relationship, with far-reaching consequences for global trade.

The confiscations -- and they just the tip of the iceberg -- show the scale of the threat. The 3,025 liters of 1-bromo-2-phenylethane seized at Manzanillo, based on density, weighs about 4 metric tons.

Since a lethal dose of fentanyl is just 2 milligrams, there was theoretically enough of this precursor to lead to the deaths of up to 4 billion people.

Manzanillo is home to Mexico's largest trading port and the site of some of the seizures disclosed by the Mexican authorities.

In November 2023, Nikkei reporters met with a Mexican man who had spent years watching the city's growth -- and its underbelly. Raul, not his real name, worked in logistics. He met the reporters at an eatery.

"Even in a restaurant like this, there would be spies from the cartels," he said as he carefully chose a table without anyone around.

Manzanillo is located on the Pacific coast of the central western state of Colima. Offshore, the waters teemed with container ships, mostly from across the Pacific.

Bringing in fentanyl precursors from China is surprisingly easy, according to Raul.

"I'm going to tell you why. The Chinese government is legally permitted to export it. Everybody can do it," he said. "Why? Because it's not an illegal substance. If I'm a medic, related to the medical industry, I can import it."

Raul said he had been approached by smugglers countless times. In a hushed voice, he explained the process.

First, Mexican drug cartels set up shell companies. They then import the precursors, falsely declaring them as medical or other products. Because these shipments follow standard customs procedures, they look like legitimate trade.

Backdoor imports are rampant, too.

Customs officials are only able to inspect a small percentage of the total cargo that comes into the country. Even if a random check does find something, smugglers have many officials on the take who can exert pressure to ensure it does not develop into a major case.

Nikkei used LSEG's shipping database to trace the distribution routes of fentanyl precursors.

Commercial vessels typically take months to cross the Pacific, stopping at ports in Asia, Oceania, North America, and Central and South America. They stay at any given port for a few hours to a few days, and even up to two weeks in some cases.

Mexican authorities seized fentanyl precursor on Nov. 30, 2022. This means that the shipment had entered Manzanillo in the preceding two weeks, and the vessels was possibly still in the port. There were 90 large vessels that met those conditions.

Of these, 58 ships, or 64%, had stopped at Shanghai, Qingdao, Shenzhen or other major Chinese ports within the past six months. Four vessels were confirmed to have traveled up the Yangtze River and taken on cargo at Wuhan in Hubei province, home to clusters of chemical plants.

Almost all of the operators of the 90 vessels in question responded to Nikkei's request for comment and denied any involvement.

"We respect and comply with all the applicable local laws and regulations around the world and will not accept legal cargo," said a spokesperson for Hong Kong-based Orient Overseas Container Line. "We have been and will continue to be in full cooperation and supporting all relevant authorities in their fight against crime when necessary."

The company said it had not heard about the seizure of the fentanyl precursor in Manzanillo.

A spokesperson for container shipping company MSC said: "We are not aware of any fentanyl being found onboard our vessels in Mexico or anywhere else in the world for that matter.

"Rest assured we would be informed by the appropriate authorities if fentanyl was found," the spokesperson added.

A.P. Moller-Maersk and state-run China COSCO Shipping did not respond to Nikkei's request for comment. In August 2019, a routine inspection by Mexican authorities uncovered 23 tons of fentanyl precursors on a Maersk vessel, Danish media reported.

Some ocean shipping lines are taking their own precautions against smugglers.

Japan's Ocean Network Express has developed a screening algorithm to detect disguised products. A spokesperson said the company continues to work on new methods, but the details are confidential.

As Nikkei's investigation moved forward, Japan's position in global drug smuggling networks began to emerge.

Mexican journalist Ricardo Ravelo has followed the fentanyl trade for many years. He received death threats from drug cartels 10 years ago, and he has traveled with bodyguards ever since.

Ravelo, known as one of the foremost experts on drug crime in Mexico, says there is a distribution route that he calls "the Yokohama connection."

"The Mexican government has detected traffic networks from Asian countries to Mexico, and Yokohama is one of the ports pointed to as an introductory point of chemical precursors that reach Mexico in the hands of criminal groups, especially the [Sinaloa and Jalisco New Generation cartels]," said Ravelo.

Japan is no longer just a destination for cocaine and other stimulants produced in Latin America. It is increasingly becoming a transit point for chemical products going to Mexico that will become precursors for synthetic drugs. According to Ravelo, Mexican authorities believe that the Port of Yokohama has become such a hub.

Yokohama is one of the busiest ports in Asia. Fentanyl precursors come in various forms and are hidden in electronics, auto parts, clothing and other goods that can easily blend in with other maritime cargo.

In October 2020, the Mexican navy and federal prosecutors jointly seized a huge amount of fentanyl precursors coming into the Port of Ensenada in Baja California.

"We received a tip that a company in Hong Kong was shipping dangerous chemicals to Ensenada via Yokohama," said navy spokesperson Erick Reyes.

In the aforementioned November 2022 case of the 3,025 liters of precursor seized at the Port of Manzanillo, 58 of the 90 ships Nikkei investigated had called at Chinese ports, and 25 of those had stopped at Yokohama.

The situation is further complicated by the emergence of low-cost e-commerce platforms. These platforms are driving an unprecedented surge in international small parcel traffic, raising the risk of illegal drugs entering Japan.

In June 2024, as part of their investigation, Nikkei reporters attempted to contact fentanyl vendors operating on the dark web. One vendor, operating under the name Emotive Pharmacy, communicated through the encrypted messaging app Telegram.

Asked whether it had shipped fentanyl to Japan before, the vendor said, "Our customs friends share a long-term relationship with us. We ship to Tokyo at least 10 times a month."

As of June 2024, Nikkei had contacted nine fentanyl vendors, of which seven said they could ship to Japan.

Many of these shipments go through Japan Post's Express Mail Service or through U.S.-based UPS as both air and maritime shipments. The fentanyl comes in many forms, including pills, powder and liquid in vials for injection. With 50 pills averaging $250, it is not particularly expensive.

The vendors said they would disguise the contents of the packages in plaster or ceramic figurines or bars of soap, or mix them in with everyday items like herbs, plant food, bath salts and jewelry cleaner.

The sales sites are repeatedly shut down and relaunched, making it difficult to pin down who is behind them.

Police deny that there is any fentanyl distribution in Japan. "We cannot confirm any arrests in Japan related to fentanyl use or possession," a spokesperson for the National Police Agency said.

But for smugglers, Japan offers an advantageous location. It is close to China, South Korea and Southeast Asia, and is connected to ports across the Pacific through maritime routes.

A total of 2,579 kg of illegal drugs were seized by customs at Japanese ports and airports in 2024, according to the Finance Ministry, the third-highest level on record and the second straight year that the figure has exceeded 2 tons. Seizures have continued at a high level into 2025.

"Given the spread of the fentanyl problem around the world, there is a strong possibility that it will spread in Japan as well," said an official in the Compliance and Narcotics Division of the Ministry of Health, Labor and Welfare. "It will become increasingly important to strengthen border controls."