Amazon.com has come under fire for removing the "Sales Rank" data for books with gay and lesbian themes.

Author Mark R. Probst wrote about the Amazon policy change on his blog Sunday.

"On Amazon.com two days ago, mysteriously, the sales rankings disappeared from two newly-released high profile gay romance books: ‘Transgressions’ by Erastes and ‘False Colors’ by Alex Beecroft. Everybody was perplexed. Was it a glitch of some sort?"

Mark R. Probst

"The very next day HUNDREDS of gay and lesbian books simultaneously lost their sales rankings, including my book ‘The Filly.’ There was buzz, What’s going on? Does Amazon have some sort of campaign to suppress the visibility of gay books?"

Probst posted a response he received from an Amazon.com Advantage member services representative about the removal of the sales rankings.

"In consideration of our entire customer base, we exclude ‘adult’ material from appearing in some searches and best seller lists. Since these lists are generated using sales ranks, adult materials must also be excluded from that feature."

The explanation from the Amazon customer service representative contradicts what a spokesperson later said about the removal of the sales rankings.

Amazon’s spokesperson blamed the sales ranking removals on a "glitch."