A probe to find the cause of an island-wide blackout last week was still under way yesterday.

Dennis Pimentel, the Belco president, added that a report on last Friday’s outage would be sent to the Regulatory Authority.

He said: “Once the investigation is complete a report will be submitted to stakeholders including the Regulatory Authority.

“Belco management and staff would like to again thank the public for their patience and apologise for the inconvenience caused by the outage and wish all our valued customers a safe and happy holiday season.”

But Jarion Richardson, an OBA MP, said last night: “Someone knows what happened.

“The public needs to know if someone needs to be held accountable and what will be done to ensure this catastrophe never happens again.”

Wayne Caines, president of Belco owner Ascendant, said on Facebook: “The investigation and subsequent reports are still in progress. They will be shared publicly – this will be a transparent process.

“As you can imagine, the report has to be in-depth as it was a significant occurrence. We must ensure we have a full understanding of what transpired.”

The fault at the electricity company’s plant at 10.20am last Friday caused an outage that affected the entire island.

A crisis management team was alerted and work started to diagnose the problem and fix it.

Most customers had power restored by 5pm the same day.

Nigel Burgess, the RA’s interim head of regulation, said the regulator had still to get Belco’s report into the cause of the power cut.

He added the RA’s role in the aftermath was to understand the root causes of the outage and to work with Belco to implement changes to “mitigate against future like-occurrences”.

Mr Burgess said the RA was in constant communication with Belco during the outage to get updates on the restoration of services, – in particular the restoration of services to the hospital, airport and Hamilton.

He added Belco also told the RA it was unable to deliver services as required under a section of its licence.

Mr Burgess highlighted that the RA issued service standards which set performance indicators for Belco.

He added: “Specifically, the indicators relating to the reliability of electricity service can have a financial impact if the utility fails to meet the annual targets set by the RA.”

The news came as Southampton was hit by another loss of electricity yesterday.

A Belco spokesman said that about 340 customers were without power for some time during the afternoon.

He added that the outage was "an isolated incident caused by a fault on a utility pole“.

A team was sent to investigate the problem and “restore power to customers as soon as possible”.