Career
He played for Latvia in Chess Olympiads and 3rd unofficial Chess Olympiad:
In 1931, at first reserve board in 4th Chess Olympiad in Prague (+7−3=1);
In 1933, at fourth board in 5th Chess Olympiad in Folkestone (+5−6=3);
In 1935, at fourth board in 6th Chess Olympiad in Warsaw (+4−4=4);
In 1936, at fifth board in 3rd unofficial Chess Olympiad in Munich (+7−7=3). In 1944 Hasenfuss was leading the Riga Chess Championship, but due to illness was forced to withdraw from the tournament. He died at a German hospital in Gotenhafen (today Gdynia, Poland).