Pre Construct Archaeology, which is carrying out the work on behalf of North East Lincolnshire Council, has carried out trial trenching and will now compile a report before deciding which areas require more detailed work and preservation.

The site, soon to be transformed into a £12m residential and retail development, could reveal clues and remains of the town's past dating back to the 13th and 14th centuries.

An earlier excavation in 1975 by the Grimsby Society for Local History and Archaeology recovered Roman and medieval pottery.

Five trenches were dug in 1994 and uncovered well-preserved archaeological deposits from the medieval period.

They included remains of 13th and 14th century buildings fronting on to Cartergate, together with associated back plots to the east.

An absence of 15th and 16th century deposits was interpreted as the result of clearance for new yards and a building in the early 17th century.

Earlier remains include what is probably a prehistoric pit, a layer containing Roman pottery and redeposited early-medieval pottery, from between the Roman period and the Norman Conquest.

The archaeological team now on site is assessing areas around the front of Cartergate and Chantry Lane for the first time. Details will be posted on boards outside the site.

The new development will feature office space, a hotel and an area of public space to be known as New Bridge Place, as part of the Urban Renaissance Programme, a partnership between the council, the Greater Grimsby Renaissance Partnership and Yorkshire Forward.

Yorkshire Forward will be funding enabling works and associated public realm improvements to Chantry Lane and the underpass linking Cartergate with St James Square. Improvements will also be made to the current Cartergate car park.

Grimsby is believed to have first grown up during the 10th or 11th centuries around the Riverhead area.