A construction worker drags a trolley down a tunnel at the site for the new Crossrail station in Tottenham Court Road, London Stefan Wermuth/ Reuters

Companies working on London's Crossrail projects have been fined a combined £1m for three separate failures.

One the incidents led to the death of Renè Tkáčik, a construction worker from Slovakia, who was killed in 2014 as a tonne of wet concrete poured onto him.

A joint venture of three companies, Bam, Ferrovial and Kier (BFK), admitted the health and safety breaches at Southwark Crown Court on Friday (28 July), following an investigation from the Health and Safety Executive (HSE).

BFK was fined £300,000 for the death of Tkáčik which, like the other two incidents, occurred in the tunnels around Fisher Street in Central London.

"The omission to implement exclusion zones in a high-hazard environment was a consistent failure in this case," said HSE head of operations Annette Hall.

"Had simple measures such as these been taken, all three incidents could have been prevented, and Renè Tkáčik may not have died."

The joint venture was also fined £600,000 for an incident involving Terence 'Ian' Hughes, who in 2015 was struck by a reversing excavator and suffered severe fractures to his right leg and injured his left knee and shin.

Less than a week later, Alex Vizitiu was hospitalised for six days, as he suffered head and hip injuries as well as a broken finger after he was hit by pressurised water and concrete debris as he helped clean the pipes used to spray liquid concrete lining.

"We believe every person should be healthy and safe at work," added Hall.

"Here, all three workers were taking part in one of the most important and challenging infrastructure projects of the decade.

"It was this joint venture's duty to protect its dedicated and highly skilled workforce. On these three occasions, BFK failed in its duty, with tragic consequences for Renè Tkáčik and his family."

On top of the £1m fine, BFK was also ordered to pay costs of £42,337.28.