HONG KONG, China -- Hong Kong police arrested five people on Friday over an accident at a concert by the city's most popular boy band Mirror that left a dancer facing permanent paralysis.

The Mirror concert on July 28 was cut short after a large LED screen suspended above the stage fell onto a group of performers, hitting one in the neck and leaving him in critical condition.

Four men and one woman, aged 40 to 63, were arrested early on Friday on suspicion of fraud and a charge of allowing an object to fall from height, police said.

Graphic footage of the accident captured by horrified fans shocked Hong Kong and prompted questions on whether safety standards were properly enforced, as well as wider discussions on workplace conditions in the entertainment industry.

A government task force set up to investigate the incident said in August that a substandard cable was used and that the screen's weight was under-reported -- though at the time it did not say who should be held responsible.

Police said the five arrested people, who worked at main stage contractor Engineering Impact and subcontractor Hip Hing Loong Stage Engineering Company, had misled authorities with their paperwork.

"They made the false declaration deliberately with a view to speed up the approval process for the show," superintendent Alan Chung told reporters.

The paperwork stated that the LED screens weighed 1,633 kilograms (3,600 pounds) collectively when the real figure was in fact 4,470 kilograms, Chung said, adding that other equipment weights had also been also under-reported.

The cable that broke during the accident was supplied by a mainland Chinese company and was not properly checked by the main contractor or subcontractor, police added.

"We could not find evidence that the (contractors) took any measures to ensure the electrical parts and equipment reached quality standards and were safe to use," Chung said.

Hip Hing Loong staff had made "adjustments" to the LED screen and the cable on the morning of the accident, but did not report any issue for follow-up, according to police.

Dancers injured

Dancer Mo Li, who recently turned 28, suffered a severe spinal injury and was in critical condition for more than a month, with doctors saying chances of full recovery were slim.

A second dancer was less seriously injured.

Last month, concert organisers Music Nation and MakerVille defended their choice of production crew and rejected accusations of cutting corners.

"We chose to hire teams that are considered top-notch in the industry... Cost is not our primary consideration," they said in a statement.

Hong Kong generally has good safety standards but a spate of recent deadly workplace accidents have heightened concerns that not enough is being done to protect workers or punish employers when avoidable accidents occur.

In September, three men were killed and six others injured after a crane collapsed at a construction site.