Planning officials are investigating waste dumping on a 22,000 square metre conservation area in Yuen Long, amid suspicions it could have come from a construction site for the MTR's high-speed cross-border railway.
Trees have been removed from land near Wong Chuk Yuen village off Kam Tin Road and dirt piled almost two metres high.
The MTR Corporation said all its waste was being dumped at designated sites.
But sources said it had been hard to find dumping sites since work on the Hong Kong-Macau-Zhuhai bridge was halted by a fatal accident in October. The waste had previously been used for fill at the bridge site near the airport.
"The bridge construction has stopped, but the high-speed railway work is still going on and generating waste," one source said. "So other land needs to be found to dump it. It's very chaotic now. People dump waste on whatever land is available."
Another source said concerns had been raised about whether the MTR was monitoring the dumping of waste closely enough.
An MTR spokesman said waste control measures were strictly followed and the site near Wong Chuk Yuen was not used. It did not respond to inquiries about whether waste was being dumped by sub-contractors.
Diggers were seen at the site near Wong Chuk Yuen village off Kam Tin Road in a South China Morning Post visit last month, but no one was operating them. Dozens of concrete cylinders were being buried. The site's northern end is surrounded by barbed wire, but waste has spilled into adjacent government land, an aerial picture shows. One of the few trees left standing was covered by spoil to the middle of its trunk.
The Planning Department said the agricultural lot, which was under a block government land lease, fell mainly in the conservation area together with the Lam Tsuen Country Park to its north. A small portion in the south is zoned for industrial use.
"Any filling of land or pond or excavation of land within the [conservation area] zone ... would require planning permission from the Town Planning Board," a spokeswoman said. "According to our records, the site is not subject to any previous application for filling of land."
She said the department would take enforcement action under the Town Planning Ordinance if an investigation proved the work was illegal.
The Lands Department confirmed filling had been done at the site. It received a complaint recently, but could not initiate enforcement action as there was no breach of the lease.
Neither department has established who was responsible or when it started. But a resident said trees were removed from the beginning of last month. The site is about three kilometres away from the MTR's construction site.
According to Land Registry's records, the land was co-owned by an ancestral hall, Tang Tak-yuk, and a company named Growth Leader, belonging to seven members of the Tang clan registered in a flat in Mid-Levels. The company has a share capital of HK$3 million. Two shareholders, Tang Hoi-yip and Tang Man-kit, had held positions in Pat Heung Rural Committee. Tang Hoi-yip holds directorships in four other companies. Tang Man-kit is listed as a director of more than 20 companies. They could not be reached for comment.
Rural affairs veteran and head of the Heung Yee Kuk, Lau Wong-fat, said the men had been well known in the area.
"Tang Hoi-yip is in his 80s and Tang Tak-yuk has died. Tang Hoi-yip seldom takes care of his land in the New Territories now. It's not surprising if someone has messed up his land without his consent."