A photo of the crude oil tanker Min Hang (sailing under a different name) taken in 2023 Photo: Michael Warrick/Marine Traffic
The Tonga Government has issued a statement denouncing any foreign vessel claiming to fly its flag.
It said Tonga's international registry of ships was closed in 2002 and the kingdom does not register foreign vessels engaged in international voyages.
"Any foreign vessel currently transmitting under the Tongan flag is doing so fraudulently and without authorization from the Kingdom of Tonga," it said.
"The Maritime Administration Office, which oversees Tonga's maritime safety, compliance, and regulatory framework has maintained strict oversight since the closure of the registry to ensure that Tonga's flag is not misused in global shipping."
It comes as analyst Mark Douglas told RNZ Pacific at least ten sanctioned vessels tracking in the East China and South China seas are falsely flying under the flag of Tonga.
Douglas said the vessels had 'shadow fleet' hallmarks, transmitting false identity signals to skirt authorities.
He said these vessels can easily transmit a false identity, doing so through the global automatic identification system (AIS), which port authorities use to stop ships from running into each other.
The first three digits of a vessel's Maritime Mobile Service Identity (MMSI) number identify a country's flag.
"You can go into the AIS receiver transmitter, and put an MMSI number which has the first three digits of any other country you want, and now when you're transmitting, you suddenly take on the nationality of that country," Douglas said.
Tonga's government said the vessels currently transmitting under the Tongan flag are part of the 'shadow fleet'.
"The Tonga Maritime Administration Office is closely monitoring this issue and is coordinating with the International Maritime Organization to safeguard Tonga's name and flag from misuse."
The government said Tonga bears no responsibility for vessels fraudulently flying its flag, but it acknowledged the reputational risks posed by false AIS data being reported widely.
The Cook Islands recently faced a similar issue with The Bertha, which flew under the Cooks flag for almost nine months in 2024. In a statement on 6 January, it said it appears that Bertha is continuing to use Cook Islands identifiers.
Numerous Cooks-flagged ships have been identified with Russia's 'shadow fleet' of vessels illicitly trading in Russian and Iranian crude oil.
