A royal burial site hailed as the UK’s “equivalent of Tutankhamun’s tomb” has been found between a pub and an Aldi supermarket in Essex.

Artefacts have been analysed by a team of experts who suggest the body may be that of Seaxa, brother of Anglo-Saxon King Saebert.

The find was made during widening work on a section of road in Prittlewell, Southend-on-Sea, in 2003 but the significance of the site has only just been realised.

Sophie Jackson, director of research and engagement for Mola (Museum of London Archaeology), said it is the earliest dated Christian Anglo-Saxon princely burial in the country, the Press Association reports. 

Archaeologists have estimated it would have taken 113 working days to build the chamber, which contained exotic artefacts from around the world.

“I think it’s our equivalent of Tutankhamun’s tomb,” she said. “It’s getting an intact version of this and seeing how everything is positioned and what he’s got with him.”

She said the site had been fully excavated because, once discovered, it was vulnerable to potential theft.

Artefacts uncovered include a lyre (a stringed musical instrument), a 1,400-year-old painted wooden box, and a flagon believed to be from Syria.

It is the first time a lyre has been recorded in complete form, and the box is the only surviving example of painted Anglo-Saxon woodwork in Britain.

Other finds included the gilded silver neck of a wooden drinking vessel used for wine, and decorative glass beakers.

“I think the thing that’s so strange about it is that it was such an unpromising looking site,” said Jackson. “It’s between a bit of railway and a bit of road, essentially a verge.

“It’s not where you’d expect to find it.”

Carbon dating indicated that the male died between 575AD and 605AD, so could not have been King Saebert, who died in 616AD.

Fragments of adult tooth enamel suggest he was over the age of six, and the size of the coffin and placement of items within suggest he was about 5ft 8in.

Jackson said it was possible it was the king’s brother, Seaxa, adding: “That may also not be correct, but that’s the best guess.

“There’s a lot of debate about whether he was a fully-fledged hairy beast Saxon warrior, or younger,” she said. “Had he died before he could really prove himself as he could have been buried with more kit?”

The presence of artefacts from other kingdoms suggest wealth, she said.

“It’s a really interesting time when Christianity is sort of creeping in and this is all possibly before Augustinian sent his mission to Britain to convert the country to Christianity so they would have been just on the transition between having pagan burials with all your gear but also having these crosses,” she said.

The chamber, which was about 13ft (4m) by 13ft (4m) and around 5ft (1.5m) deep, contained some 40 artefacts.

Some of them will be displayed at an exhibition at Central Museum in Southend which opens to the public on May 11, and research will also be published in two books.

The project was funded by Southend-on-Sea Borough Council and Historic England.