A British museum is to return a lock of hair that the Ethiopian government considers a national treasure.

It was cut from the head of Emperor Tewodros II, who killed himself rather than be taken prisoner by the British during their 1868 invasion of Ethiopia.

His seven-year-old son Prince Alemayehu was taken to the UK along with looted treasures. He became a favourite of Queen Victoria before dying aged 18.

His remains are kept in Windsor Castle despite campaigns for their return.

Strands of Emperor Tewodros II's hair were given to the National Army Museum in London 60 years ago.

The museum told the BBC it had decided not to make photographs of the hair public out of respect, because the matter was "too sensitive". The remains are described as two pieces "no bigger than the size of a two-pence coin".

The National Army Museum has now agreed to return the artefact, but says it is not returning any other items of African origin.

"It's definitely not a precedent," a spokesperson for the museum told the BBC.

"That's the only one that's been requested. They have to be formal, written requests to the director with a case".

The BBC's Emmanuel Igunza in Addis Ababa says talks about the process of repatriation with the Ethiopian government are set to begin within the next few days.

The move has reignited demands for the UK to return all the looted artefacts on display in British museums.

Historians say 15 elephants and 200 mules were needed to cart away all the loot from Maqdala, the emperor's northern citadel capital.

Ethiopia lodged a formal request in 2008 at various British institutions for the return of the treasures worth millions of dollars taken from the site.

The announcement comes at the end of a year-long commemorations marking 150 years since the Battle of Maqdala.

The so-called Napier expedition, often described as the largest military offensive by the British empire in Africa, saw thousands of soldiers deployed to face Emperor Tewodros II.