An unlicensed door-to-door salesman threatened to ‘smash some windows’ if turned away from a Suffolk home.

So-called ‘Nottingham knockers’ were also spotted taking photographs of other properties in the area this week.

Suffolk Trading Standards advised people not to buckle to pressure from pushy salesmen.

The warning follows reports of Nottingham knockers in Woodbridge, Campsea Ashe, Wickham Market, Kesgrave and the IP4 postcode area of Ipswich.

Trading Standards officers also received reports around Bury St Edmunds earlier in the week.

A spokesman said reports described some salesmen asking for donations when declined custom, with one male threatening to “smash some windows” if the occupant closed the door, and others seen taking photos of properties.

The spokesman added: “These individuals are claiming that they have just come out of prison, and are on a youth offending scheme, attempting to mend their ways.

“They then try to sell the householder everyday household products at very high prices.

“Trading Standards always advises residents to refrain from buying at the doorstep and not to buckle to pressure from salespeople offering supposedly one-off, ‘buy it now’, low prices.

“These Nottingham knockers work in gangs across the country and are not involved in any officially recognised offender rehabilitation programme.

“Many do not possess pedlar’s certificates issued by police.

“If you are approached at the door, please refuse to buy.”

Meanwhile, Suffolk Trading Standards received reports of a bogus caller pretending to be one of their own officers.

A Suffolk resident received a from an individual called Darren, claiming to be investigating the sale of a stolen item on Facebook.

“The resident was fully aware that what they had sold was not stolen and so did not engage further,” said a spokesman.

“It is a criminal offence to impersonate a trading standards officer and can carry a prison sentence of up to 10 years.”

There were almost 15,000 impersonation scams reported nationwide by UK Finance members between January and June – up 84% on the same period of last year.

Trading Standards officers can be verified via the consumer helpline on 0808 223 1133.