Glazing business Zenith Home Improvements has ceased trading.
Staff were told on Tuesday the business had been seeking a new buyer, but bosses had been unsuccessful.
A member of staff, who wished to remain anonymous, said 150 to 200 people have been made redundant across the East of England.
The jobs have been lost in a call centre operations site in Norwich, as well as in sales.
MORE: Car dealership set to close making five people redundant According to the company's LinkedIn profile, its site in Norwich is on the Abbey Farm Commercial Park in Horsham St Faith.
BBC Watchdog launched an investigation into Zenith Home Improvements in June.
According to the BBC, Zenith Home Improvements is owned by parent company the Kairos Group.
The Kairos Group has been approached for comment.
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