A worker at a water bottling plant in Christchurch apparently welding while straddling on a raised forklift.

More complaints have been made about activities at a Christchurch water bottling plant where migrant workers are alleged to be routinely involved in unsafe work practices.

A range of agencies are now involved, looking at issues ranging from trespassing, waste disposal, immigration, and the building's safety.

The plant was supposed to begin operating on Monday, but it had yet to receive its consent to bottle water. It already has consent to extract water, amounting to around 4.3 million litres of water per day, which had been transferred with the land which used to house the Kaputone Wool Scour.

ALDEN WILLIAMS/STUFF The former Kaputone wool scour in Christchurch, now home to a water bottling plant.

Local contractors have reported wide-ranging issues at the site, revealed in photos that Stuff obtained. These include a worker purportedly welding at height while straddling a raised forklift, and what appears to be structural issues with the building.

The plant's owner, China-based Cloud Ocean Water, declined to comment on the allegations through its New Zealand-based director, Feng Liang.

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SUPPLIED Workers regularly stood on forks whilst undergoing construction work, a witness said.

Worksafe has issued notices to the company, and Christchurch City Council had investigated whether workers were sleeping on site.

A council spokeswoman said it found no evidence this was the case, but it was continuing to investigate potential building code and Resource management Act breaches.

Images seen by Stuff, however, appear to show a worker sleeping while ensconced in boxes, with a mattress visible nearby. Another image shows what seems to be clothes being washed in buckets in a bathroom.

SUPPLIED A worker standing on a forklift beneath a scissor-lift. If the scissor lift failed, the worker would be crushed.

Neighbours have reported activity at the site late at night, including workers running across the train tracks through private property.

A KiwiRail spokesman said the company was "aware of issues associated with water bottling plant construction staff trespassing in its Belfast yard."

KiwiRail was taking steps to make the site as secure as possible, including increasing the amount of fencing, he said.

One contractor, who asked not to be identified so he could speak openly, alleges he was supposed to begin work at the factory on Monday but left immediately upon seeing the conditions.

"I walked in on Monday, saw it, and walked away. It was unbelievable."

He said few of the people on the site, including supervisors, spoke English, a detail corroborated by another contractor.

The machinery inside appeared to be new and came from Australia, he said, and was divided into three sections.

Environment Canterbury said its staff visited the site on Monday for reasons it would not specify because the investigation was ongoing. It is understood it may relate to waste disposal.

A spokesman for the Ministry of Business, Innovation and Employment, which handles immigration issues, said its staff had not visited the site.

It is understood it has received at least one complaint regarding activity at the premises, however.

The plant had been contentious within the community, local community board member Aaron Campbell said.

There were concerns about the effect of the water take and how the plant had gone ahead without public consultation.

"I think the consensus is pretty well defined, what people are thinking," he said.

"They don't like the idea of water being exported for a number of different reasons - they're taking away a resource, they're not paying for it, and all these plastic bottles, where are they going to go?"

The water take was of particular concern given the current dry spell and the larger water bottling plant planned for next door, he said.

Residents had also been concerned about health and safety practices.

The plant is one of at least 70 water bottling operations known to be consented in New Zealand.

It would be one of the largest in terms of volume; it is surpassed, however, by the plant being installed on the site next-door, which has permission to take around 7 billion litres per year.