Tether冻结伊朗资金达5.5亿美元，参议院调查质疑USDT

Tether freezes approximately $550 million in Iranian-linked USDT, Senate probe questions the effectiveness of sanctions

Tether announced that it will freeze approximately $550 million in USDT related to the Central Bank of Iran and its sanctions network in 2026. The disclosure was issued on September 28, the same day Senate investigators released their findings, pointing out that the USDT has become a core component of Iran's shadow financial system. Tether views the freeze as evidence that "U.S. dollar tokens based on public books are not an effective tool to circumvent sanctions." However, Senate investigators focused on the time gap: Some of the frozen wallets had accumulated funds since 2021, but were not identified until years later.

April and July accounted for most of the total frozen amount.

On April 23, Tether said that in response to information provided by the U.S. Treasury's Office of Foreign Assets Control (OFAC) and U.S. law enforcement agencies, it assisted the U.S. government in freezing more than $344 million of USDT at two addresses. The next day, OFAC listed the two addresses as identifiers associated with the Central Bank of Iran. According to TRM Labs, the two wallets have received approximately US$370 million in funds since March 2021, involving nearly 1,000 transactions, but only approximately US$25 million has flowed out. Most of the balances were accumulated before the end of 2023 and have remained almost unchanged since then. TRM Labs believes this model is more like a reserve infrastructure than an active payment wallet.

In July, OFAC added four addresses located on the TRON network to the Central Bank of Iran's designated list. Chainalysis data shows that these addresses received approximately $165 million in stablecoins and held approximately $131 million when Tether implemented the freeze. Tether listed the two actions as major components of its total freeze of approximately $550 million in its announcement. However, based on its own data, the total is approximately $475 million, and the company did not explain the difference.

Freeze action Number of wallets Life cycle inflow Freeze USDT amount April 2026 2 Approximately US$370 million (TRM Labs data) Approximately US$344.2 million July 2026 4 (TRON Network) About US$165 million (Chainalysis data) Approximately US$131 million Subtotal disclosed 6 Approximately US$535 million Approximately US$475.2 million Tether's 2026 total amount None None About US$550 million

Why did Iran's Central Bank buy USDT

今年1月，Elliptic识别出伊朗中央银行通过某些钱包获取了至少5.07亿美元的USDT，Elliptic称该数字仅为下限。泄露的文件显示，2025年4月和5月的两笔购买是用阿联酋迪拉姆支付的。由于伊朗难以获得美元清算或代理行服务，USDT提供了一种可行的替代方案。Elliptic指出，这些资金有助于支撑里亚尔汇率，并使银行系统之外的跨境结算成为可能。在2025年6月之前，大部分USDT流向了伊朗最大的加密货币交易所Nobitex。Elliptic表示，这一模式符合向国内市场注入美元流动性的特征。据Elliptic称，Tether已于2025年6月15日将几个与央行相关的钱包列入黑名单，冻结了约3,700万USDT。

2025年6月，亲以色列的黑客组织Predatory Sparrow攻击了Nobitex。此后，Elliptic观察到与央行相关的资金通过跨链桥和更长的交易路径进行转移。部分资金随后到达了Shelbit，这是一家总部位于迪拜、已被OFAC制裁的交易所。2026年6月2日，OFAC还将Nobitex、Wallex、Bitpin和Ramzinex四家交易所列入制裁名单。Elliptic估计，这四家交易所之间的加密资产发送或接收量至少为400亿美元。

参议院调查人员称USDT已成为伊朗的首选渠道

《华尔街日报》报道，参议院永久调查小组委员会的民主党成员得出结论，USDT已成为伊朗相关网络（包括与真主党有关的网络）的重要支付机制。根据对该调查的报道，调查人员审查了846个受制裁的伊朗关联钱包，发现约84%的钱包主要或完全依赖USDT。

该调查始于数月前。6月4日，该小组委员会资深议员理查德·布卢门撒尔（Richard Blumenthal）致信Tether首席执行官Paolo Ardoino，引用了他所谓的“未能防止非法使用的明显失败”。他询问Tether是否已冻结所有与这四家伊朗交易所相关的USDT，并询问其是否曾拒绝将其怀疑从事非法活动的钱包列入黑名单。这些仍然是立法者提出的指控和问题。

Tether的案例依赖于其冻结能力

Ardoino辩称，USDT不是规避制裁的有效工具，因为每一笔转账都在链上可见，且一旦当局标记地址，Tether即可将其列入黑名单。余额仍然可见，但无法再移动。扣押比特币通常需要私钥或合作托管方，而USDT的发行方直接控制代币合约。该公司表示，它与全球67个国家的340多个执法机构合作，已冻结与非法活动相关的超过49亿美元，其中超过24亿美元是与美国当局合作的成果。

Compared to the size of the entire network, the amount associated with Iran is negligible. According to Messari data, in the fourth quarter of 2025, USDT handled US$4.4 trillion in transactions on the chain, of which 88% had transaction amounts less than US$1,000. Most of the traffic is daily payments, a far cry from central banks storing hundreds of millions of dollars in just a few wallets.

Reserves that others can close at any time

Iran needs digital dollars because it has lost access to real dollars. USDT provides it with global liquidity and round-the-clock settlement services that do not require correspondent banks. But it also makes its reserves dependent on a private issuer working with U.S. authorities. The April freeze showed the cost of this dependence: five years of accumulated holdings become unavailable in one day.

The same wallet also confirms the Senate's concerns. These wallets began receiving funds in March 2021 and will not be frozen until April 2026. On-chain records make it possible to rebuild its history and lock in remaining funds. However, the actual effect of this transparency while funds are still flowing is unclear.