The Polish newspaper cited Austria's Der Standard as saying that Warnig was a long-time friend of Russian President Vladimir Putin.
Warnig "worked for the Stasi" under the code name "Arthur" beginning in 1974, Der Standard reported, according to Poland’s Rzeczpospolita.
According to Stasi documents reviewed by The Wall Street Journal more than a decade ago, Warnig left the East German intelligence service in 1989 with the rank of major.
During the 1980s, when Putin served in East Germany as a KGB agent, Warnig helped him recruit spies in the West, The Wall Street Journal reported in 2005, citing former colleagues of the two men.
After the Soviet Union fell in 1991, Warnig and Putin again joined forces, this time to promote the spread of capitalism, according to The Wall Street Journal.
According to the nord-stream2.com website, Warnig "had several functions in the German Democratic Republic’s government from 1981 to 1990, including roles in the foreign trade ministry and the Cabinet."
Nord Stream 2 is a USD 10.5 billion gas pipeline being built under the Baltic Sea. The 1,200-plus-kilometre link is expected to have the capacity to send around 55 billion cubic metres of Russian natural gas a year directly to Germany, while bypassing the Baltic states, Poland and Ukraine.
Warsaw and Washington have both strongly criticised the project amid concerns that the pipeline will make the European Union more dependent on Russian gas.
US President Donald Trump on Friday signed a massive defence policy bill that includes a measure to punish companies involved in work to build the controversial pipeline.
(gs)
Source: rp.pl, wsj.com, nord-stream2.com