The NSW Rural Fire Service has completed an investigation into a fire near a Telstra pit outside Orange on May 4.

READ MORE: Triple zero network affected

The investigator was also able to rule out all causes apart from an electrical fault and arson, but was unable to narrow it further.

The fire did not originate in the pit. 

RFS Chief Superintendent Ben Millington said a comprehensive investigation was undertaken, but it was not unusual to be unable to arrive at one factor.

“The original report of lightning was ruled out as a result of data provided by the Bureau of Meteorology,” he said. 

Intermittent interruptions to emergency calls affected NSW, Victoria and Western Australia.

A Telstra spokeswoman said the company operated millions of kilometres of fibre cables, which were at risk of damage every day from construction work, weather, vandalism and fire.

“These risks are top of mind when we design our network and we build in redundancy for key services,” she said. 

The spokeswoman said Telstra would consider the RFS’s findings as part of its response to the incident.