The manuscript was due to be auctioned at Sotheby's in London, with an expected sale price of Ô£300,000-Ô£500,000.
Alexandre Rachmaninoff stopped the sale with an injunction. The dispute could end up in England's highest court unless Rachmaninoff and the collector who found the manuscript can reach agreement.
The 320-page manuscript was discovered in a Swiss cellar last September. A European collector contacted the Telegraph's Geoffrey Norris, a music critic and author of a book on Rachmaninoff, and asked him to authenticate it.
According to Norris, the manuscript, containing all the original orchestration for the work and missing the first four pages and title page, was "unquestionably genuine."
Rachmaninoff's Second Symphony, his most popular and frequently played orchestral work, was completed in 1907, when the composer was in staying in Dresden. The symphony's first two performances, conducted by the composer, were in St. Petersburg in January of 1908. The manuscript had not been accounted for since it was used to prepare the first published edition of the score later that year.