Poundland in Anglia Square remains shut after it was flooded by water seeping from the old cinema above.
The Magdalen Street store first closed on Monday (December 19) after it became covered in water from leaking pipes in the former Hollywood Cinema which is situated on the floor above.
Water can be seen dribbling from the store across the pavement in front with a number of safety signs and barriers erected.
The shop has now been closed for three days.
A sign in the store window reads: "Due to flood, we are closed, sorry."
Since this morning a new sign has been installed saying the shop was shut due to "unplanned maintenance".
Anglian Water was called to the scene but workers were unable to fix the problem as it was a private leak.
A spokesman for the water supplier said: "This is a private leak - not from our network - coming from internal pipes in the old cinema.
"The leak has been isolated by our team and the maintenance company who look after the building have been informed.
"The leak maintenance is now their responsibility."
The cinema, which once hosted the film premiere of Alan Partridge: Alpha Papa, has been empty since it closed in 2019.
A Poundland spokesman said he was unable to confirm when the store would reopen but said the issue was currently being dealt with by the shopping area's maintenance team.
He said: "There was a leak from an old water tank in the disused cinema above.
"The landlord of the premises is working on fixing the problem, but we don’t yet have an idea when it will be fixed.
"Obviously we can only re-open if it’s safe to do so.
"We're sorry for the inconvenience, but while the store is closed customers can visit our retail park shop and two town centre stores."
Poundland also has stores in St Stephens Street, Castle Quarter and Riverside Retail Park.
An Anglia Square spokeswoman said she was unable to comment on the incident.
No other stores have been affected by the incident.
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