The power of citizen science unfolds by the comparison of public research data with thousends of DTC-test-results. In the case of Ötzi the Iceman the Y-haplogroup found in research papers as terminal is so far G2a2a1a2-L91/PF3246/S285 (b37 position 21645555 G->C).
Update August 2020: Ötzi has no known paternal line descendants (more Alpine men Y-DNA would be needed to find if any share all his so far private Y-SNP mutations). The nearest Haplogroup to Ötzi is G-Z6494 which is so far present in Pakistan, Arabia, Marocco, Germany and Italy. https://www.yfull.com/tree/G-FGC5672/ In 2014 only the South German men results where known so it was assumed Ötzi’s Y-Haplogroup might have expanded from the Central Alps. But now we know all his modern nearest known Y-Cousins are much more widespread and it is a old Western Eurasia haplogroup.
2014 Text: Ray Banks, the very active and skilled citizen scientist for Y-Haplogroup G has unveiled the L91 substructure, finding also the position of Ötzi as G2a2a1a2a1a-FGC5672 (b37 position 8524959 C->T) so far shared only with a German DTC-sample (FGC result of Kraus family in Thüngen, Unterfranken, Bavaria, haplotypes in G-PF3146 project). Previously Ray also found Ötzi was positive for the upstream L166 SNP. It would be very interesting to get the sampled L91+ Tyrolean and additional Y-sequences from the Central Alpine and European area for comparison to the new L91 structure (tentative tree positions in Blue):