Morgan Sindall shut down work on the site at noon to give workers an impromptu refresher on health and safety.

Developer Muse had previously said that the shutdown was “routine” but it later emerged that it was, in fact, called due to the accident.

According to local reports, a man suffered a fall and fractured his leg and two ribs in the incident at the Broad Street development.

Work is ongoing on the £107 million city centre scheme which is expected to open this summer.

A spokesman for Morgan Sindall said an investigation had been launched into the cause of the incident.

He said: “There was an accident on Friday which occurred within the Marischal Square site boundary, and resulted in injury to a member of our supply chain.

“We are currently conducting an internal investigation into the circumstances surrounding the incident.

“Ensuring the safety of everyone working on our sites is our number one priority and we routinely hold periodic stand-down days to refresh all site personnel of the health and safety policies and procedures in place to protect them.

“We have taken the decision to stand the site down for the afternoon today for that purpose.”

SNP group leader Stephen Flynn said: “Despite the controversy surrounding the development itself, what’s important here is that a person has been injured.

“It’s the first incident of this type I’ve heard of on the site and it’s a bit disappointing this has only been brought to my attention through the media.

“Nevertheless, I am sorry to hear about this injury and I hope the person is on the mend soon.”