Two subsidiaries of the deep-sea mining firm The Metals Company have launched legal proceedings against the International Seabed Authority (ISA), in order to block an investigation into their non-compliance.

Nauru Ocean Resources Inc. (NORI) and Tonga Offshore Mining Ltd. (TOML) are both subsidiaries of The Metals Company, and brought their cases before the Seabed Disputes Chamber of the International Tribunal for the Law of the Sea (ITLOS) in Hamburg, Germany on 2 July.

The lawsuits seek provisional measures, similar to an injunction, to suspend an active regulatory compliance investigation into potential contract breaches. T

The ISA inquiry was launched by a unanimous vote of its member states in July 2025 following allegations regarding TMC’s engagement with domestic US permitting processes.

At the core of the filings, NORI and TOML argue that the ISA has violated international due process and non-discrimination principles under the UN Convention on the Law of the Sea (UNCLOS). 

The companies claim that the regulator identified them as non-compliant contractors without providing prior notice, access to evidence, or an opportunity to defend themselves during what they describe as a closed-door inquiry.

The timeline is particularly critical for NORI, whose current deep-sea exploration contract is scheduled to expire on July 22, 2026. The company claims the ISA is intentionally withholding a five-year contract extension due to the ongoing investigation. 

TOML’s contract expires in January 2027. Its separate application focuses on commercial reputation management, arguing that the public non-compliance designation hinders the company’s ability to secure the private investment required to transition from exploration to commercial mining.

The legal challenge seeks to freeze the regulatory oversight mechanism while a full tribunal determines the legitimacy of the ISA’s investigation. 

Campaigners have noted that this litigation represents an important test of whether an international tribunal can stop a directive approved unanimously by a global coalition of member governments.

Environmental advocacy groups have criticised the legal maneuver. 

Sebastián Losada, Senior Policy Adviser at Greenpeace International, characterised the lawsuits as blatant corporate bullying which is attempting to circumvent international regulatory oversight.

“This lawsuit is an effort by would-be deep-sea miners attempting to block an investigation into their own contract breaches,” Losada said. “It demands that governments stand strong and take urgent action to defend global cooperation.”

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