Tensions between Hong Kongers and mainland Chinese visitors bubbled to the surface this week as the two jostled for beach space during a long holiday weekend.
The incident once again highlighted how much Hong Kongers feel put out in their own city by mainland Chinese who are visiting Hong Kong by the millions - and also how the local government has failed to act on their concerns.
On Wednesday, local media across Hong Kong carried scathing reports of about "700 to 800" bags of trash left on the remote Ham Tin Wan beach in Hong Kong's New Territories by hundreds of campers, allegedly from mainland China.
Many mainland visitors reportedly paid between 300 to 400 Hong Kong dollars ($A50-$A70) to Chinese camping organisers, according to Mingpao Daily, although the campsite is public and intended for just 10 four-person tents.
The incident at Ham Tin Wan prompted more than 90 complaints, according to Hong Kong's Agricultural, Fisheries and Conservation Department, although it was far from a unique case.
"This week is almost an 'emergency week' with the amount of trash and even underwear left behind" at beaches across Hong Kong, according to Robert Lockyer, the director of operations at the Aquameridian Conservation and Education Foundation.
"People come for three or four days and when they leave, they literally leave everything. I have seen bras, underpants, socks, condoms, piles of toilet tissue and human excrement in piles at the back of beaches," he said.
Hong Kong's media often points a finger in such cases at visitors from mainland China, depicting them as uncouth, messy and unaware of social norms - although locals also flock to the same beaches and campsites on holiday weekends.
Vivienne Tang, who visited Ham Tin Wan on Sunday before the large tour groups, told dpa that conditions "didn't look that bad" although the earlier visitors had left their own trash.
"We did see a pile of rubbish that looked like a group of [people] had left it there. There were bottles and leftovers in tied up plastic bags," she told dpa. "I assume it was a group that had a picnic there and must have gathered all their rubbish, but then left it on the beach for someone else to carry away."
Hong Kong reunified with China in 1997, but 140 years of British rule and long-standing international influence has given the city a separate identity from the mainland.
Many Hong Kongers feel that their identity is under attack from large numbers of Chinese tourists and migrants on one front and declining political freedoms on the other.
Between January and March, more than 12 million Chinese visited Hong Kong, according to the Hong Kong Tourism Board.
The swelling number of visitors and migrants means that locals find themselves competing with new arrivals for everything from hospital beds and vaccines to flats and milk powder - and, increasingly, green space and beaches.
In 2014, 100 Hong Kong lifeguards went on strike to protest the rising number of tourists, particularly from China, at local beaches and pools.
But Hong Kong's government rarely acts to limit the number of Chinese visitors, despite local resentment aired online and in the media. Meanwhile, the government has sought to squash political protests against Chinese rule.
The government may soon make it illegal to mock the Chinese national anthem. It has also punished lawmakers for staging protests of Chinese rule when they took their oath of office.
In such a climate, even a local beach can take on extra significance.
Conservationists say there are small steps the government could take to improve conditions.
"We criticise and we are very quick to judge the tourists for doing this, but, in reality, there is not enough signage on the beach. There's not enough rubbish bins," said Lockyer, the conservation foundation director.
"The government knew there was a large number of tourists coming to Hong Kong this weekend. They should have had more people patrolling the beaches," he said.