The Japan Times - Swedish authorities inspect worksite conditions at steel startup Stegra

As well as the police, representatives from the Swedish Work Environment Authority and the Swedish Tax Agency, were among those who visited the company's Boden site.

Local media reports said police officers had inspected the documents of several workers among the 3,000-strong workforce before taking some of them away.

Swedish newspaper Aftonbladet reported that some 60 police officers had been brought in from across the country to take part in the inspection.

"It is a joint workplace inspection carried out by the authorities," police spokeswoman Maria Fredriksson told AFP. She declined to comment on how many officers were involved.

Fredriksson said the inspection was not due to any specific case, but she said they were aware of the risks involved given the large sums of money being invested in projects in the north.

"We know that this presents both opportunities and risks of criminals exploiting the situation for their own gain," Fredriksson said.

They would make a report on their findings in the coming days, she added.

Karin Hallstan, head of communications at Stegra, confirmed the inspection.

Given the size of the construction site and investment "you have to expect that the authorities will want to carry out checks from time to time".

- Start-up by delays -

Stegra is currently constructing a brand new steel mill which will produce steel using technology the company says gives off 95 percent less CO2 emissions than traditional methods.

When it first announced plans for a new plant in 2021, it was called H2 Green Steel.

It had an ambitious target of starting production in 2024, and aimed for an annual output of five million tonnes of steel -- more than all of Sweden's current annual output -- by 2030.

The ambitious start-up has however been marred by delays, and has still not begun production. It lowered its initial production targets and its finances have recently come under scrutiny.

In October, Stegra announced another round of financing to bring in an additional 10 billion kronor ($1 billion) to cover higher project costs.

Swedish media has also recently reported that some 40 workers from Turkey and Romania, working for a subcontractor, had not been paid.

Observers have started making comparisons to another former leader of the Sweden's green industrial boom, battery maker Northvolt.

Northvolt was seen as a cornerstone in European efforts to catch up with Chinese battery producers before production delays and a debt mountain led it to declare bankruptcy in March.

Behind Stegra is investment firm Vargas Holding, which was also a co-founder of battery maker Northvolt.

M.Ito--JT