SEAL team member Matt Bissonnette - who wrote his book No Easy Day under the pen name of Mark Owen - was given the knife by Ernest Emerson, the owner of company Emerson Knives.
He carried it with him for eight long years, including the May 1, 2011, raid that ended with the killing of Osama.
The auction raised a total of $35,400 (Rs 19.35 lakh) for the knife. The complete fund-raiser garnered more than $75,000 (Rs 41 lakh) for charitable organisations. The knife buyer’s identity remains unknown.