Archaeologists have uncovered the remains of what is believed to be a Roman villa and bathhouse under land earmarked for construction of a supermarket in Britain.

According to a report on Friday by the BBC, archaeology and heritage group Oxford Archaeology made the discovery, which features mosaic brickwork.

The site of the discovery is in Warrington Road, in the town of Olney in Buckinghamshire in South-east England. The site is currently being prepared for the construction of a new outlet for discount supermarket chain Aldi.

The excavation was commissioned by property development company Angle Property, due to the site’s proximity to the existing Roman site at Olney.

Archaeologists said the mosaic had “vibrant colours and intricate decorative patterns” made up of blue, white and red tiles.

Oxford Archaeology wrote on Facebook that it believes the mosaic belongs to the Durobrivan group from the East Midlands which, according to history websites, could mean it dates as far back as the 4th century.

After consulting with government agency Historic England and the local authority Milton Keynes Council, Oxford Archaeology said the mosaic has been preserved in its original place.

The brickwork will be protected with materials, to allow construction of the supermarket to continue without damaging it.

Oxford Archaeology’s senior project manager John Boothroyd said the team had anticipated finding “notable Roman remains” due to the site location, but the mosaic discovery “far exceeded these expectations”.

Mr Boothroyd said that “to be able to preserve remains of this quality and importance is a brilliant outcome”.

Angle Property’s executive director Anthony Williamson said the discovery has taken everyone by surprise, and promised that the process “will be fully recorded”, and information about it will be published.