The court order temporarily blocks any distribution of Robert McCorkell's estate or transfer out of New Brunswick, Ottawa-based lawyer Richard Warman stated in an email.
McCorkell left his collection to the U.S.-based National Alliance when he died in Saint John nine years ago, but the estate has remained unsettled.
The injunction was obtained on Monday on behalf of McCorkell's sister Isabelle McCorkell, who will be challenging the bequest on public policy grounds, Warman said.
"I anticipate that other groups will intervene in support of the application in the coming days," he said.
Anti-racism groups had planned to try to stop the National Alliance from receiving the items, fearing they could be sold and help spark a rebirth of the neo-Nazi group that has been in decline since its founder died more than a decade ago.
Initial estimates pegged the collection, parts of which have been exhibited in Saskatoon and Ottawa, as being worth up to $1 million.
But probate court documents obtained by CBC News showed McCorkell's estate willed to the National Alliance is valued at about $250,000, with about $89,000 in outstanding liabilities.
That leaves about $161,000 for the white supremacist organization, which is based in West Virginia.
The collection includes Greek and Roman coins that are thousands of years old, an ancient Iranian sword, Neolithic arrowheads and an Egyptian stone tablet from the 13th Dynasty, according to a 55-page appraiser's report from August 2010.