Bones from an ancient graveyard were uncovered by gas engineers in Lynn’s Saturday Market Place on Friday.
Gas worker Paul Jipp found the bones, believed to belong to a child, along with the remains of a leather shoe as he was excavating a hole close to the Pizza Express restaurant.
Mr Jipp, a gas service layer, discovered the pelvis and finger bones while digging below a gas main.
The bones could date back to the time the church was built, between the 11th and 13th centuries and were buried in a section which had once been the town’s cemetery.
Mr Jipp and his colleagues are working in Saturday Market Place on a five week project to replace the gas mains.
He said: “When I found the hip bone I knew it was an old grave. I also found bits of leather which looked like the shape of a heel. There were also two to three bits of wood which could have been bits of the coffin or struts for the grave. It was pretty well preserved.
“You always find bits and pieces when you do this job and working next to a church you do think you could find something like an old grave.”
Work on replacing the gas mains was halted briefly on Friday while the police and West Norfolk Council’s Environmental Services were called.
The bones, thought to be part of a pelvis, some finger bones and others not identified at the time were taken away.
A National Grid spokesman said: “Although not an everyday occurrence, we do occasionally find bones in the excavations we dig whilst replacing gas pipes. Proper procedures were followed and the relevant authorities dealt with the situation quickly.
“Although only a rough guess, the bones were thought to be from the time the church was built around the 1100s.”
The council has passed the bones to the Rev Chris Ivory, vicar of Lynn Minster, for re-burial.
He said: “The churchyard to the south of the minster was consecrated in the 1620s. Prior to that all the burials were to the north.”
Manager of True’s Yard Museum Lindsey Bavin said the site was used as a cemetery prior to the 1600s.
She said: “This area was used by the townspeople to bury their dead. The clergy would be buried on the opposite side of the church.
“They had an incredibly high infant mortality rate then.
“The area where they are digging was used as a shambles with stalls right up to the minister. It was a very busy area of the town.”