Union chiefs have called for standardised Covid-19 testing following an outbreak on board a North Sea platform.
Initially four cases were identified – but a further 13 positive tests were recorded over the weekend.
Production on the rig – which is stationed 150 miles east of Aberdeen – was halted in response to the outbreak, and bosses are removing workers from the platform.
A leaked internal update shows Ithaca does not currently operate a policy of Covid-19 testing before workers are transported to their platforms.
However, the firm plans to introduce pre-mobilisation testing from this week.
John Boland, regional officer for the Unite union, said: “The Covid outbreak on the Ithaca FPF-1 is very concerning, and shows that even with precautions put in place there is still the risk of an outbreak offshore.
“It is also concerning that no pre-mobilisation testing was being done, and although it is not perfect, it has been shown to be an effective barrier at stopping Covid getting offshore.
“We call on all operators to ensure that adequate testing is in place, and show that they really do put the health and safety of their workforce first.
“We would like to see it [standardised pre-mobilisation testing], but at present, those operators testing are all different.
“UK Government have agreed to offshore workers, being classified as essential, and given asymptomatic testing by NHS England, but not been agreed in Scotland yet. This is the best chance of getting consistent testing across operators.”
Backing the call for standardised testing is Scottish Conservative energy spokesman and north-east MSP Alexander Burnett, who said: “It’s extremely concerning to hear of a cluster of cases especially in a confined area such as an offshore platform.
“This again highlights the need for mandatory testing which should be standardised right across the sector before workers are mobilised.
“We know the virus spreads when people are in close proximity to one another and are coming from different parts of the country – the exact conditions faced by offshore workers.”
Only the minimum number of people required to operate a shut-down platform – believed to be 13 – are being kept on board, with the rest being flown onshore.
Bosses will only begin to increase the number once it is safe to do so, and a deep clean of the rig has been scheduled.
All workers, whether they remain on the rig or not, will be tested for coronavirus, and those who have returned onshore will be offered safe transport home or accommodation in Aberdeen.
The Health and Safety Executive (HSE) is in contact with Ithaca over the outbreak.
A spokesman said: “HSE is aware of the situation at the FPF-1 oil production vessel and is in contact with Ithaca Energy to ensure transmission risk of coronavirus are brought under control.”
In a statement, Ithaca said: “The safety and wellbeing of our workforce is our top priority. Production on the FPF-1 has been shut in to ensure the safety of all those onboard.
“We are moving to minimum manning, conducting a thorough deep clean, and implementing daily testing of those essential personnel remaining onboard the platform.
“All personnel down manned from the asset have been tested upon returning onshore and contact tracing conducted where appropriate.
“We are introducing pre-mobilisation testing for all crews mobilising to Ithaca Energy operated assets this week.
“We will not seek to restart production until we can start up in a safe and controlled manner.”
A Scottish Government spokesman said: “Testing for offshore workers is provided by private companies. However, asymptomatic testing can be deployed in the event of an outbreak on request of local public health professionals.
“Testing is being significantly expanded in Scotland with a focus on those most at risk, including patient-facing healthcare staff, emergency and elective admissions, and most recently all designated visitors to care homes, visiting professionals to care homes and care at home staff.
“The expansion is fully aligned with the advice from the senior clinical and scientific advisers who reviewed our testing strategy and is only possible because of increases in our testing capacity, delivered through our new regional hub laboratories and supply of new testing technologies.
“We are keeping all testing policies under active review, in line with expert advice and the changing prevalence and local epidemiology.”
At least three people on board have contracted the virus, while around 10 others are being quarantined, according to two sources.
It is understood that Covid testing is being arranged for workers remaining on board the CNOOC installation, which lies around 115miles north-east of Aberdeen in the North Sea.
CNOOC was contacted for comment.