Collectors of Judaica are being warned of a rise in fake items being sold online.
Internet market sites such as eBay advertise hundreds of items including yads, figurines, kiddush cups and havdalah spice boxes.
But buyers have reported incidents of pieces being advertised as 19th century Russian antiques which, when purchased, turn out to be cheap, modern replicas.
Jacob Nightburg, from Stamford Hill, north east London, bought a spice box set on eBay for 120 euros [£105] from a seller based in Germany.
When it was delivered to him, Mr Nightburg became suspicious.
He said: “I did think it was a bit strange, the boxes were decorated with naked male cherubs. I contacted the seller and they were desperate for me not to report them. They gave me my money back.
“This was a person who was selling from Germany, but shipping items from Poland.
“Looking around eBay you see that Judaica items do sell well. People buy this stuff expecting it to be genuine. Dreidels are everywhere on eBay but they are often rough wood and horrible. People are being conned.”
Judaica specialist Jonathan Fishburn said the scarcity of high-quality genuine pieces means the market for fake items is growing.
“It’s not just eBay, there’s a lot of this rubbish around, in the markets generally and even in some auction houses. It’s a big issue.
“Someone showed me a supposedly 18th century yad (Torah pointer) from Eastern Europe, but it was not even a good copy; it was something that just would not even have existed back then.”
Mr Fishburn said collectors should check the authenticity of online dealers and study images of pieces before paying.
“People need to be very careful. Use some common sense,” he said. “I’d be reluctant to spend a lot of money with someone I have not come across before. If it looks too good to be true, it usually is.”
A guide page set up by a concerned shopper on eBay warns others to be wary of “counterfeit silver” Judaica. It highlights newly-made wedding rings and an “antique silver jewellery box”, in the shape of a computer, as among the most audacious fake items.
An eBay spokeswoman said: “People need to check the seller’s feedback score and be sure who they are buying from. We have a trust and safety team in Dublin who are happy to look into any dubious sales and check the sellers are acting legally. If they are not, then they will be removed from the site.”