"The probe by Germany's Federal Criminal Police Office is examining why the yacht they believe was used to carry out the operation journeyed into Polish waters," WSJ wrote in a Saturday investigative report. "Other findings suggest Poland was a hub for the logistics and financing of last September's undersea sabotage attack that severed the strongest bond tying Berlin to Moscow."

The new allegations are based on the findings of the German investigation, which Polish authorities have reportedly been seeking and struggling to gain access to. If true, it could escalate already boiling tensions between Warsaw and Moscow, and put Russia further on a war-footing with NATO. 

"German investigators have fully reconstructed the entire two-week long voyage of the Andromeda—the 50-foot white pleasure yacht suspected of being involved in one of the biggest acts of sabotage on the continent since World War II—and pinpointed that it deviated from its target to venture into Polish waters," WSJ continued.