Residents have been calling police and Trading Standards about vans turning up in streets and opening their doors to illegally sell chainsaws and televisions among other items.
There have been reports of people paying a high price for the items to find they are cheap and of poor quality.
Sgt Chris O’Leary said: “We have had reports of illegal selling of chainsaws and gardening equipment in numerous locations including Horsham, Littlehampton, Worthing, Uckfield, Hastings, Lewes, Mid Sussex and Rye in recent weeks.
“As a police service we need to reduce the risk to people and warn them to be wary of buying from cold callers. If it sounds too good to be true, it probably is. However, at this time, we have not linked the goods to any theft offences.”
West Sussex County Council has advice about cold callers here along with information about its Buy With Confidence scheme.
For consumer advice on trading standards issues, contact the Citizens Advice Consumer Services line on 08454 040506.