One worker has been killed, and three injured, in an explosion at a factory run by Danish wind sector supplier Welcon, according to media reports in Denmark.

The accident occurred at the company's recently-expanded factory in the Give area of Denmark, and resulted in the death of a 41-year old Portuguese national, according to a report by Danish news website Vejile Amts Folkeblad, which quoted Stig Simonsen, a deputy police inspector at South East Jutland Police.

The same website suggested that two of the injured workers, also Portuguese, suffered life-threatening injuries as a result of severe burns. All four workers were described as experienced welders, and none were recent hires.

Welcon produces specialised steel solutions to the renewables sector and is a major global supplier of wind turbine towers, with recent expansion into production of floating foundations.

Welcon managing director director Jens Pedersen told Vejile Amts Folkeblad that the company was not yet able to offer an explanation about the causes of the accident

Welcon recently completed a billion-dollar expansion at its main manufacturing base.

The company's website stated that the expansion encompassed "new large plate preparation and welding shops, a very large new surface treatment facility and some additional storage, office and welfare facilities, enabling Welcon to produce the largest offshore towers and the innovative Stiesdal floating foundations."

The new build-out was designed for Lean Production with the most modern and advanced robot technology in both the welding departments and the surface treatment facility, the website states.

The same Vejile Amts Folkeblad report said a 32-year-old Polish construction worker lost his life due to a fall during the construction of the factory, back in February.

Welcon has not yet responded to a request by Recharge for information about the accident and possible causes.