From there, Niko set up an enterprise representing the interests of the large American-based Texaco corporation in Germany and became a kind of European 'super-manager' for the firm.
But he had a double life, which was not revealed publicly until after the war. In 1936 he quietly joined the Bremen branch of the Abwehr or secret service and at the outbreak of hostilities was appointed full-time Sonderfuehrer or Specialist Leader. Niko became no less than the main authority in Germany about President Franklin D Roosevelt and the White House, and on the United States position leading up to its entry into the war.
The Game of Foxes (Pan 1973) by Hungarian journalist and intelligence officer Ladislas Farago described Niko as
'...a big and ruddy faced man who spoke English fluently in the American idiom - a delightful companion with exquisite taste for beautiful women, good food and vintage wines, an especially wonderful escort for tired businessmen relaxing on trips to Germany.'
Niko appeared more sophisticated than 'the uncouth air and repulsive swagger of the big-shot Nazis' and hid his real allegiance by entertaining American friends with jokes ridiculing Hitler.
In this way, and by his own network of spies in Germany and the United States, he gathered day to day private activities of the US President and discovered details of support for Britain and preparations for war, at a time when the United States was supposedly neutral.
One of his agents, Waldermar Othmer, became a stevedore earning 45 to 65c an hour at one of America's most important naval bases, at Norfolk, Virginia. From here he was able to build up a detailed mosaic for Niko of American naval power, including the names of ships and the types and ranges of their guns.
Niko devised an ingenious cipher using patent numbers (see example below) in which he was able to gather information from his agents in the United States without attracting suspicion and wrote a Satzbuch or code book along these lines for the Abwehr. He was also one of the Abwehr officers behind a successful operation to unscramble secret allied radio conversations including between Roosevelt and Winston Churchill. It meant Germany knew when the invasion of continental Europe was imminent and that Italy was about to capitulate to the allies.
In 1940, from his contacts in American corporations, and especially the oil industry, Niko was able to obtain an accurate 58-page study showing that 50,000 war planes were required by Roosevelt for the war effort and that this was within the capability of US industry. The study, and his reports about ship and tank production, convinced Niko's Abwehr associates about the titanic power of the United States. Admiral Wilhelm Canaris, head of the Abwehr, took the report about the planes to Hitler but the Fuehrer shrugged it off and threatened to punish those who believed or circulated such 'defeatist rubbish'.
According to Ladislas Farago, Hitler said,
'You must be out of your mind to take such crap seriously. 50,000 rubber tranquilizers maybe, for the poor little babies of America. But 50,000 planes? Don't be ridiculous!'
It meant that although Niko continued to gather authentic information about the growing American war potential, there was no place to take the intelligence. However it convinced Canaris of the hopelessness of the German cause and was a reason he became a plotter of peace and involved in two abortive plots to assassinate Hitler. Canaris was led to the gallows barefoot and naked and hung on Hitler's orders on April 9 1945, just weeks before the end of the war. What happened to Niko is unknown.
The following 1940 example, from one of Niko's American agents, is of Niko's code. This gave war-time Germany details of US military power and activities:
'Subject: Our Opposition Filed Against USA Patent Applications.
Against the various claims claimed by these patents we think that the following issued patents can be used:
Claim No. 1 USA 528 127
DRP 505 985
DRP 561 838
French patent 529 727
Claim No. 2 USA 612 001
USA 611 095
British patent 531 937
USA 626 197
Claim No. 3 British 552 830
USA 616 606
We furthermore think that in general USA patent 552 205 and USA patent 557 010 will be found noxious by the examiner…'
When Niko decoded the letter it read: [528 127] March10th [505 985] departed [561 838] Genoa [529 727] Marseille [611 095] American liner [531 937] President Polk [626 197] carrying [552 830] 2500 crates [616 606] inflammable goods [552 205] 1000 barrels [557 010] gasoline.