Books by Israeli authors could be removed from Scottish libraries as part of a council's boycott policy.
The ban is enforceable in libraries run by West Dunbartonshire Council, which covers towns and villages west of Glasgow.
It is thought the move may be illegal under local government legislation. Israel supporters said it aligned the council with Iran and Saudi Arabia and was an "outrage".
No books have so far been removed from any of the authority's libraries as councillors say censorship is "not in the spirit" of their boycott, but it is understood that officials are prepared to rule on a book-by-book basis.
That would mean unelected council staff could decide whether books by authors such as Amos Oz, David Grossman and Benny Morris are made available to readers.
West Dunbartonshire adopted a boycott of Israeli goods in 2009 after a motion was proposed by a Scottish Socialist Party councillor following the Gaza flotilla incident.
Arieh Kovler, director of the Fair Play Campaign Group, which opposes boycotts of Israel, said: "Banning access to knowledge for political reasons is nothing short of censorship. West Dunbartonshire must reverse this policy or their libraries will become an international laughing stock."
A council spokesman said: "It would only be in a very limited number
of circumstances that this boycott would apply."