Google has quietly sold one of its unfinished four-story barges, many months after starting construction on the mysterious structure in Maine, it's claimed.

A local paper in Portland reported on 1 August that the search giant has sold the barge it had docked there, and that the barge will be scrapped. The barge, which Google assembled in Connecticut and towed to Portland last October, reportedly carried 63 shipping containers and was to be towed again to New York City upon completion and opened for an invite-only crowd.

Google's barges first popped up on the shores of San Francisco and Maine last autumn. Each had direct ties to Google, spawning numerous stories about what they were and potentially contained. Reports claimed they would eventually be docked in either San Francisco, Los Angeles, or New York, and that they were part of a $35 million project called Hangar 3.

Each barge was likely intended to be floating retail store for Google Glass and would feature up to 80 stacked shipping containers and rows of sails. Other reports have said they would house dazzling showrooms outfitted with chrome features, floor lighting, party decks, and interchangeable containers that could create new spaces for Google X events.

READ: Google Barges are $35M floating retail stores

It's not clear why Google sold the barge in Maine, but at least one other identical barge still exists in Stockton. Like its twin, the Stockton barge, which surfaced in San Francisco last year, remains unfinished, and there is much speculation about what Google plans to do with the sole hangar.