A Shropshire woman who admitted failing to report finding a possible piece of treasure has received support from an online community of metal detecting enthusiasts who claim she could be the victim of a miscarriage of justice.

Kate Harding, 23, of The Hawthorns, Ludlow, was given a three-month conditional discharge last week and ordered to pay £25 costs for failing to report the finding of a piedfort to the south Shropshire coroner.

The case was the first prosecution of its kind in the country. Forum administrators for Detectorist.co.uk contacted the Shropshire Star saying they thought she should not have been prosecuted under the 1996 Treasure Act as it appeared she had found the piedfort before the Act was passed.

The silver piedfort is believed to date from the 1300s. It is a specially-struck heavy coin which was originally made for presentation. The name comes from the French for “heavy weight”.

A person posting on the website said: “My maths figure this find to pre-date the 1996 Treasure Act. If she was given it by her mother before she died when she was nine and had found the coin a while before this date whilst with her mother.”

Maria Hawkaluk, a police spokeswoman, said: “The woman pleaded guilty in court. An inquest has yet to be held to establish whether the item is treasure and where and when it was found.”

Harding told Ludlow Magistrates Court last week that she and her mother had found the piedfort and her mother gave her the object when she was nine years old and had died soon after.