Namibian authorities are being urged to freeze plans to extend a port on the Shark Island peninsula – meant to support green hydrogen production along the country’s south coast – after the discovery of unmarked graves and artefacts relating to the Herero and Nama genocide.

Leaders of the Nama ethnic group had already rejected a proposal by national port authority Namport to expand a facility on Shark Island – a heritage site sacred to the community – to facilitate green hydrogen production and export by German company Hyphen Hydrogen Energy.

Now, non-profit research agency Forensic Architecture says it has located sites of executions, forced labour, imprisonment and sexual violence on the island that occurred when the German empire used it as a concentration camp (1905–1907).

Historical accounts suggest people who died in the camp were “thrown to the sharks”, said Forensic Architecture, members of which have called for a moratorium on development projects in the area and for wider investigations into possible underwater graves.

“Any prospective construction needs to be stopped until these sites are fully protected, and thorough studies of the remains on the camp have been done,” said Agata Nguyen Chuong, a Forensic Architecture researcher, as quoted by The Guardian (UK). “[The] constructions will further desecrate and compromise Shark Island as a site of archaeological, historical and cultural heritage.”

Hyphen, a Namibian-registered green hydrogen development company, was specifically formed to develop green hydrogen projects in the mostly desert African country for international, regional and domestic supply.

The German company is a joint venture between renewable energy group Enertrag SE and investment and project development company Nicholas Holdings. Hyphen plans to produce about 2mn tonnes of green ammonia a year at a project in the southwest of the country, from about 7 gigawatts (GW) of renewable energy and 3 GW of electrolyser capacity.

However, some locals view the proposed port expansion serving Hyphen as a new form of German colonisation, where African resources are extracted for the benefit of European markets, Voice of America (VOA) reported in April.