Episode four will air at 10am on Thursday, 30 September 2021 and will feature the council's trading standards team, led by service manager Colin Briggs.
In the episode, investigators take an estate agent to court for failing to tell buyers their new flat was a fire risk. The £200,000 flat had the same cladding as Grenfell Tower, but the buyers weren't told until half an hour after the sale was completed. By then, it was too late to pull out.
Meanwhile, a special police unit investigates a cruel new scam targeting the elderly.
Defenders UK is a documentary series following the work of enforcement officers as they battle to protect the public from the crooks and conmen endangering our health, families and homes.
Reflecting on the episode, trading standards manager Colin Briggs said: "The day of filming was a full on but enjoyable experience. The production company were extremely helpful in offering tips as to how to get across such a serious issue which had caused so much mental and financial stress for the public whom we serve.
"The programme will hopefully highlight some of the serious problems that any of us can experience when we buy products online and what steps we can take to avoid these. I hope you enjoy watching this episode and that it gives you confidence to both protect yourself and your friends and family when to make online purchases."
Catch Colin and the trading standards team on BBC One at 10am on Thursday, 30 September for episode four of Defenders UK.