Apple has completed the necessary paperwork to start expanding its Prineville data centre campus in the State of Oregon in the north West of the US, local newspaper Bend Bulletin reported.

Recently, the company announced the construction of a whole new building in the same hub but will now expand the existing infrastructure until the end of the year, local officials expect.

The expansion will consist of final pods, each measuring over 35,000 sq ft. Two of the eight planned pods where built at the start of the project in 2012.

A structural permit application estimates the value of the expansion at under $6 million.

Another application of nearly $600,000 will be used for interior works, including the sewage system.

Crook County Commissioner Ken Fahlgren told the newspaper: "We’re excited to see the beginning of the last portion of the building."

The expansion led Crook County to request an expansion of the city’s borders to include the potential new data centre in its limits. The county asked for the area to be re-branded from ‘exclusive farm use’ to ‘light industrial’.

The expansion of the Oregon’s campus is the second this year, after in late March Apple expanded its Nevada data centre in Reno to support iCloud growth.