Heirs of the late philanthropist Hannah Carter have gone to court to block the University of California at Los Angeles from selling a Japanese garden that the university purchased with donated funds, reports the Los Angeles Times.

In a suit filed Monday, the plaintiffs contend the sale breaches a contract in which University of California Board of Regents committed to maintain the Hannah Carter Japanese Garden permanently.

UCLA won a 2010 court ruling clearing the way for an auction it says will fetch more than $4-million to put toward endowments and faculty positions and free the school from nearly $140,000 a year in costs for maintaining the garden. The school is accepting sealed bids, which it is slated to make public May 23.

The university purchased the garden with funds from a 1964 bequest by longtime regent Edward Carter, Hannah Carter’s husband, and pledged in a 1982 amendment to “retain the garden portion in perpetuity,” according to a Huffington Post commentary by Charles Birnbaum of the Cultural Landscape Foundation, which opposes the sale.

A UCLA spokesman said the university has followed the appropriate legal steps to proceed with the sale and “intends to contest the [Carter heirs'] lawsuit.”