Two men were arrested on Thursday after 'acting suspiciously' and 'causing a disturbance' close to where the Duke and Duchess of Cambridge were travelling on their Royal Tour of Australia.
According to the Evening Standard, witnesses said the men got within 10 metres of the royal couple and were stopped by police who ordered them to remove their clothes.
Kate and William were reportedly not aware of the incident, and Prince George was not with the couple.
One of the men was wearing a mesh vest with pro-Israel stickers attached.
The pair were seen in the village of Winmalee, where the Duke and Duchess had arrived to hear the story of survivors whose homes were burnt to the ground in devastating bush fires last October.
Press Association reports that a spokeswoman for New South Wales Police said: "At 1210 today police stopped and spoke to two men aged 37 and 21 who were allegedly harassing members of the crowd who were gathered at the corner of Single Ridge Road and Vista Road, Winmalee.
"The pair were moved on from the area prior to the motorcade coming past."
According to the Daily Mail, one of the men were taken away by police, while another was released. Before being arrested, the pair were seen talking on headsets.
The mood lightened when the royal couple arrived at Echo Point, Katoomba, to see the famous Three Sisters rock formation and were greeted by around 3,000 well-wishers lining crash barriers.
William and Kate, who wore a Diane von Furstenburg wrap dress and wedges, were welcomed by cheers from the crowds and walked down to a platform to see the majestic views across the Blue Mountain range.
Before leaving the royal couple went on a short walkabout meeting the crowds who had been patiently waiting to meet them.
Sarah Barman, 22, said: "William came over and said 'what a great spot for a picnic'. He was so charming, he was lovely, I've been waiting three hours but it was worth it."