NME reports that security staff at London's O2 arena were told to ask fans wearing shirts featuring the band's ex-guitarist to remove them before entering, and if they refused to do so, to then turn them away.
When pressed as to whether this included fans sitting at the back of the arena that could not be seen from the stage, a security guard replied: "This is what we were told."
When a fan who was forced to remove his shirt was asked why he thought the band had requested this, he said he believed that "if [frontman Axl Rose] saw me wearing the shirt, he might have stormed off stage".
Rose has previously referred to his ex-bandmate as a "cancer better removed", and Slash has claimed that Rose "hates his guts".
Guns N' Roses have already run into controversy on this UK tour for their late arrivals to the stage, with one Manchester gig finishing at 2.15am.
Watch the video for Guns N' Roses classic 'Paradise City' below: