Shetland Quality Construction Limited has ceased trading after entering into liquidation.
The move to wind up SQC comes over a year after the company’s managing director, Ivor Smith, staged at protest at the official opening of the new Anderson High School.
The event was attended by the Scottish government’s education secretary, John Swinney.
Mr Smith claimed the company had been left almost £2 million out of pocket for work done preparing the groundworks for the new school.
At the time, Mr Smith said he was considering taking legal action against main contractor Morrison Construction.
Morrison later said in a statement that SQC “failed to complete the works as contracted”. It said the company was subsequently replaced by other sub-contractors, and that the company’s claims surrounding payment were “unwarranted”.