The retail arm of Australia Post has banned the sale of three literature classics amid concern over racy passages and graphic sex scenes.

Crikey understands that two weeks ago, staff at 848 PostShop outlets across the country were ordered to pull the Popular Penguin titles Lolita, The History of Sexuality and The Delta of Venus from shelves after customer complaints. All three books contain celebrated sexual encounters and lurid language.

Before their removal, the titilating trio were displayed in a prominent position on orange stands provided by the publisher. One PostShop employee told Crikey that they were now “out the back” after “a memo from headquarters”.

Curiously, another controversial title, Lady Chatterley’s Lover, appears to have escaped the dragnet, despite repeated references to “fucking” and the use of the word “cunt”.

A spokesperson for Australia Post, Alex Twomey, confirmed the ban this morning, saying the titles were “inappropriate for a mainstream shop like Australia Post”. He said the government-owned corporation had received the books unsolicited from Penguin.

“It was purely a decision around whether it fitted our stores. That also extends to DVDs and many other different products,” Twomey said. When pressed by Crikey, he was unable to name the exact selection criteria that led to the decision to remove the licentious titles from sale.

However, one postal worker, who did not want to be named, said the books were removed because of “customer complaints” over “inappropriate passages”. Requests for the books at other outlets were met with a awkward silence. However, Crikey understands that in some shops, the Penguin stands, containing up to 50 titles, have been completely shielded from view.

Lolita, the famous 1955 novel by Vladimir Nabokov depicting underage s-x, and the notoriously florid Delta of Venus, by Anais Nin, are top-20 Popular Penguin bestsellers. The less popular History of Sexuality, by French social theorist Michel Foucault, examines the repression of human desire, but has still shifted hundreds of copies.

Penguin Australia sales director Peter Blake told Crikey he had “no idea” why Australia Post had removed the offending titles. He said had never encountered a similar objection to their content from other retailers.

“We were certainly surprised by Australia Post’s reaction,” Blake said.

Blake was unable to say what the book ban would mean for Penguin’s bottom line. “Hundreds” of books were now wending their way back to Penguin headquarters, he said. The 99-strong Penguin collection retails in bookstores across the country for $9.95 and is apparently one of the most popular initiatives in the history of publishing.

It is unknown which particular Delta of Venus passage Australia Post objected to.

However, the second page of sultry novel, described in promotional material as containing a “glittering cascade of sexual encounters”, contains the following stanza:

“Her sex was like a giant hothouse flower, larger than the Baron had ever seen, and the hair around it abundant and curled glossy black.”

Lolita, which has sold hundreds of thousands of copies since its first edition, opens with the classic line “Lolita, light of my life, fire of my loins”, describing the 12-year-old object of Humbert Humbert’s affections.

Although the raunchiness is comparatively lacking in Foucault’s History of Sexuality, the word “sexuality” in the title may have sent alarm bells ringing.

Lady Chatterley’s Lover, which remains on sale, was famously banned in Australia until the 1960s and its overturning remains a watershed for the domestic anti-censorship lobby. The written account of the British trial, The Trial of Lady Chatterley, was also blacklisted.

In January, Australia Post was embroiled in another censorship controversy after it outlawed postcards promoting Adelaide Fringe Festival artist Greg Taylor’s show “Cunts and other Conversations” which included graphic depictions of female genitalia. Horrified mail sorters were told not to process the cards and they were returned to Mr Taylor with a warning they were in breach of Commonwealth statutes.

Next week, departing Australia Post managing director Graeme John is expected to front the Senate Environment, Communications, Information Technology and the Arts Committee as part of its obligations as a government-owned corporation. It is unknown whether the book ban will be discussed.