According to the data, several minutes past 0100 GMT the plane flew south of Bornholm heading to northwestern Poland, where it circled for about an hour above land before flying at around 0244 GMT to the area where the gas leak was reported.
It came as close as some 24 kms (15 miles) to the reported leak site, circled once and flew towards the Russian exclave of Kaliningrad, a frequent focus for surveillance, analysts say.
Polish, Swedish, Danish and German ministries of defence were not immediately available for comment.
There is flight data missing between 0339 GMT and 0620 GMT, but on its way back, around 0700 GMT, the plane flew some 4 kms north of the reported leak site.
A partial flight map from US-based tracking website Radarbox has been used complemented by data provided by Sweden-based Flightradar24 to reconstruct the P-8’s path.
Flightradar24 data showed the plane taking off and landing at Reykjanes peninsula in southwestern Iceland, where Keflavik Air Base is located along with reported P-8 hangar facilities.
The data emerged as the Baltic remains a front for Cold War-style tensions in the aftermath of Russia’s invasion of Ukraine, according to analysts who caution it is impossible to establish with certainty the reason behind specific military flight paths.
“The Baltic is a very active sphere of confrontation with lots of probing and an endless chess game,” said UK-based defence analyst Francis Tusa.
Poland’s Prime Minister Mateusz Morawiecki said on Thursday the pipeline burst was “most likely” the work of Russian special services, citing information from Western allies.
Western governments and officials have so far avoided pointing a finger directly at Moscow, while Russia has rejected any allegations of responsibility as “stupid”, blaming the United States and its allies instead.