Female football fans were made to show their bras to stewards during security searches, a supporters' group has said.
Grimsby Town fan group the Mariners Trust made the allegation in a letter to Stevenage FC after the two sides met on Saturday.
It said some fans wearing underwired bras were also asked by stewards at the Lamex Stadium if they could feel them.
Stevenage FC said it was "investigating the matter" before making any further comment.
The club would not comment when asked by the BBC whether the searches were standard procedure or due to an increased security risk for that match.
The checks, carried out by female stewards, but which the supporters' trust said were "in full view of male stewards, fans and police", have been described as "a gross invasion of privacy".
The letter from the supporters' group alleges stewards asked some female fans "if they could feel their bras" if they told them their bras were underwired.
The group also says children as young as five were subjected to full body searches and supporters had items that were not listed as being banned confiscated, such as "contact lens solution, cough sweets and medication".
The letter also said a female steward was posted inside a male toilet, adding: "The steward was asked to leave by Grimsby Town supporters, but she refused despite the fact several male stewards and police officers were stood outside."
The Mariners Trust described the treatment of supporters as "amongst the worst our fans have experienced in decades of travelling across the world to watch football."
The letter concludes by calling on Stevenage FC to address the "serious failings" as a "matter of urgency... to ensure no other visiting team's supporters are treated as animals in the way your club did on Saturday".
Hertfordshire Police has also been contacted for a response.
Source: BBC NEWS