Conservative author Dinesh D’Souza on Friday posted pictures of top White House staffers Steve Bannon and Sebastian Gorka posing with him and his new book, which argues that the modern Democratic Party practices tactics promoted by fascist leaders like Mussolini and Hitler.

Dinesh D’Souza just deleted his tweets with photos from Steve Bannon’s office. Here are the screenshots: pic.twitter.com/F77C3cjWXY — Christina Wilkie (@christinawilkie) August 4, 2017

Promotional material for “The Big Lie: Exposing the Nazi Roots of the American Left” reads: “The Democratic left has an ideology virtually identical with fascism and routinely borrows tactics of intimidation and political terror from the Nazi Brownshirts.” Ironically, Gorka has received a lot of press attention for his ties to ultranationalist groups in his parents’ native Hungary that have been accused of anti-Semitism.

It is illegal for federal employees to use their public offices to endorse a product, and executive branch conduct rules prohibit accepting gifts worth more than $20.

D’Souza’s book retails for less than that, but Larry Noble, senior director and general counsel of the Campaign Legal Center, said the pictures still raised “serious issues” about whether Bannon and Gorka had endorsed it.

“Gorka and Bannon each posing for a picture in their office with D’Souza while holding his book raises a serious issues of whether they violated the ban,” Noble told TPM in an email. “I think a reasonable person would assume that the picture would be used to publicly suggest endorsement of the book.”

“I wonder whether they warned him it could not be used for publicity,” Noble added.

The White House press office did not respond to TPM’s request for comment on the photos.

D’Souza deleted the pictures from his Twitter account soon after he posted them, but later shared a cropped version of the photo with Bannon, alongside a graphic with a link to the book’s website.

Met with Steve Bannon at the White House today to discuss how President @realDonaldTrump can flip the accusation of fascism back on the Left pic.twitter.com/m4KlV4jqYZ — Dinesh D'Souza (@DineshDSouza) August 4, 2017

The original photos appear to have been taken in Bannon’s office; the large white board checklist in the background has made news before, when rabbi Shmuley Boteach posted a photo of himself and Bannon posing in front of it, prompting analysis of Bannon’s prioritized agenda items.

Previously, at the urging of the Office of Government Ethics, the White House “counseled” Kellyanne Conway for promoting Ivanka Trump’s clothing line on national TV from the White House briefing room, with official White House imagery in the background.

This post has been updated.