A British overseas territory is being urged to return the remains of 325 formerly enslaved people to their ancestral kingdoms in Africa, or potentially face legal action. The remains were excavated in 2008 when an access road to a new airport was being built on the remote South Atlantic Ocean island of St Helena. They were held in storage for 14 years before being reburied. A master plan was drawn up for a “dignified reburial” and memorialisation and to protect up to 10,000 other remains in the African burial ground in Rupert’s Valley from which they were removed, described as “the most significant physical remaining trace of the transatlantics slave trade on Earth”. Despite endorsing the plan, the St Helena government, led by an appointee of the UK Foreign Office, has failed to honour it, according to its co-authors, Annina van Neel and Peggy King Jorde. They cite the lack of a memorial marking the site where the 325 were reburied and the fact that a national conservation area has not been created to protect the original burial ground. Van Neel, who was the airport project’s environment officer when the bones were uncovered, has enlisted the help of State of the African Diaspora (Soad) to repatriate the 325 and prevent further desecration of the site. The St Helena claim is one of many issued this month by Soad, which is recognised by the African Union, seeking restitution from countries including the UK, institutions and individuals. Van Neel, whose fight for a proper reburial of the remains is detailed in the film Buried, published by the Guardian on Tuesday as part of the Cotton Capital project, said: “As a young African woman finding something that she didn’t even know she’d lost – finding a piece of her identity, of her history – I’m still trying to make sense of how global and yet how personal this whole significant site is. “I always used to say, I don’t want to make this political, and then I think with the reburial I realised how political it really is, because who has charge of this heritage of the sacred site, and who has claimed charge of it? “And that’s why, for me, I had to take it back to Soad, to take it back to the African continent, to some sort of authority that I and those remains would deem their own authority – those people in the ground that can’t speak for themselves.” St Helena’s £285m airport was intended to help connect one of the most isolated inhabited islands with the rest of the world. It was once labelled the “world’s most useless airport” because high winds made landings difficult. Those buried, including 3,000 children, were victims of the “middle passage”, and were among more than 25,000 Africans who were removed from illegal Portuguese slave vessels and quarantined on St Helena during British abolition efforts in the mid-19th century. Although labelled “liberated Africans”, many were shipped on to the British West Indies to continue working for the crown as indentured labour. Those who stayed – and died – on St Helena were confined in overcrowded and unsanitary conditions, employed in the lowest economic occupations and lacked food. King Jorde, who visited St Helena at Van Neel’s request because of her experience in fighting to preserve African burial grounds in the US, said part of the reason repatriation was necessary was that “the United Kingdom insists upon considering these people liberated when they were not and [it is] perpetuating a lie about what actually happened to them”. She described contested burial sites as “battlegrounds” and said efforts to preserve them were a “revolutionary act of remembrance”. In support of their various claims, Soad and the International Commission on Heritage and Culture (ICHC), which have been mandated by many states, nations and indigenous territories, cite various international codes and conventions. They include the Unesco convention on the means of prohibiting and preventing the illicit import, export and transfer of ownership of cultural property; the Unidroit convention on stolen or illegally exported cultural objects; the code of ethics for museums, and a 2019 European parliament resolution to identify and recover looted art. More claims will follow the letters already sent as part of what Soad and the ICHC are calling a “class diplomatic action”. They have said that if their requests for “open dialogue” are not complied with – recipients have 30 days to reply – they are “ready to take this matter to the international courts”. The letters state: “We are calling on the western nations and related entities to restitute and return the stolen, looted, pillaged cultural goods, works of art and human remains which were taken unlawfully and return back to the rightful legal and lawful owners. “We also make this call with respect to African and indigenous American Indian human remains which are unceremoniously laying in western burial grounds, such as on the Island of St Helena, as an example.” Van Neel contrasted the efforts taken on St Helena to preserve Napoleon’s empty tomb – which has a trust overseeing it – with the treatment of the African burial site. King Jorde said of the site: “It’s part of the larger story for those of us who are descendants [of enslaved people] living in America and recognise what the transatlantic slave trade was all about. It’s sort of that missing link.” A St Helena government spokesperson said it was considering the Soad letter but that “significant progress” had been made towards delivering the recommendations of the master plan, describing it as “a live document containing multiple phases of delivery”. They said work was continuing to fund and build a memorial and interpretation in Rupert’s Valley, adding that the burial sites “have been formally recognised and allocated plot numbers in the Land Registry. As parcelled land belonging to the crown estate, no development is permitted at these sites, avoiding any further disturbance.”