The worker flew into the Solomons with about 80 other Chinese nationals, many of whom will construct stadia for the 2023 Pacific Games.
The Covid-19 Oversight Committee said the worker passed a package to a Chinese national outside of quarantine, who owns a hardware store in Honiara.
The Solomon Times reported that person had now been quarantined at the Pacific Casino for 14 days.
The Ministry of Health said it was continuing to investigate the breach.
