A groups of football fans have complained after they were told to "lift their tops up to show their bras" as part of security checks over the weekend.
The Mariners Trust, who represent around 3,000 Grimsby Town FC fans, complained to officials in Stevenage after their game on Saturday 18 August.
The checks were carried out by female security officials but all in "in full view of male stewards, fans and police" in what the group has described as a "gross invasion of privacy"
Stevenage FC said it was "investigating the matter."
The letter also claims that children as young as five were subjected to full body searches, while others were simply waived through.
The group also complained about the long list of items that were prohibited from being brought into the grounds including contact lens solution, cough sweets, medication and a small bottle of hand sanitiser, which the group pointed out is permitted on an aeroplane.
The letter also says that a female steward had been 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."
Jon Wood, the chairman of the Mariners Trust, concluded the letter by saying: "As outlined above we believe there were a number of serious failings by your football club which need to be addressed as a matter of urgency, not just for any future visits by Grimsby Town fans, but also to ensure no other visiting team's supporters are treated as animals in the way your club did on Saturday."