A former JPMorgan staffer who sources identified as Chirayu Rana has been accused of making fabricated sexual-harassment claims against a high-ranking executive at the bank after an internal investigation found no evidence of wrongdoing, The Post has learned. Multiple sources told The Post that 35-year-old Rana, now a principal at investment firm Bregal Sagemount, is the man who brought the bombshell lawsuit against Lorna Hajdini earlier this week. Rana’s suit, filed on Monday under the pseudonym John Doe, accused the 37-year-old executive director of turning him into her “sex slave” by drugging him with Rohypnol and Viagra and threatening to slash his bonus if he did not comply.…