For many people they are the most essential item to pack for a long flight. But now there is a chance that passengers might have to remove them from their hand luggage when passing through airport security. We’re not talking about laptops this time, but books.

Security staff at certain America airports have begun searching for items made of paper at checkpoints under a pilot scheme that could see screening measures for US flights become ever more invasive.

Air passengers in Missouri and a handful of other test airports, including Los Angeles, Boise, Colorado Springs, Detroit, Fort Lauderdale, Boston Logan, Lubbock, Munoz Marin in Puerto Rico, Las Vegas McCarran and Phoenix Sky Harbour, were made to undergo separate checks for books and food items last month.

As someone who brings multiple books when traveling, this will not be a quick thing. I will be hated in TSA line as they flip through pages. https://t.co/xKAk3LRiyD — AliceAyers (@AliceAyers) June 25, 2017

Passengers screened under the new process were asked to take all reading material and food out of their carry-on luggage and place them in a separate bin.

Staff working for the TSA were then tasked with fanning through each book’s pages.

Staff working for the TSA can fan through a book’s pages Credit: Getty

While the TSA claimed its screeners will not pay any attention to the content of a passenger’s reading material, concerns have already been raised that certain reading matter - such as books with political or religious content - will get more attention from staff than others, creating the potential for discriminatory practices when it comes to selecting passengers for extra screening.

One reason for the new measures, reported by the Sacramento Bee news organisation, is that the move will free up space in full-to-bursting carry-on bags so that x-ray machines will be able to better see what is in bags.

How about no? Some of us travel with a lot of books and don't particularly want nosy TSA agents looking at them — Meg 💜✨ (@sassylibrarian1) June 25, 2017

"It's always been a series of insults," Julie Sze, a University of California professor who experienced the test procedure at Sacramento, told The Bee. "Books, magazines, food, those are like my three treasured things. It feels personal on a whole different level."

The pilot scheme currently excludes TSA pre-check lanes, which are set up for travellers who have previously submitted applications to be granted a quicker checking-in procedure.

John Kelly, the Department of Homeland Security Secretary, told Fox News Sunday that the extra searches are likely to be rolled out to airports nationwide.

He also said that a ban on laptops in carry-on luggage was still being considered for all international flights in and out of the US.

"Some items, such as chocolate and books, are dense and can obscure other items when passing through the x-ray," the TSA said Credit: Getty

In a statement, the TSA told The Bee that the agency has in the past year been "adjusting screening procedures at select US airports on a trial basis in an effort to improve screener performance at the checkpoint."

It added: "Travellers at select test locations may be asked to place certain electronics and other items in a separate bin for screening in an effort to de-clutter baggage. TSA will evaluate the results at these test locations to determine if any future checkpoint procedures should be altered."

The Wall Street Journal reported last week that TSA officials had said screeners will be more engaged with passengers at the tables where people put items into bins before passing through the X-ray machines. The official told the Journal that screeners will ask people to remove more items, including electronics, from their bags, but those items may differ from line to line and airport to airport.

Officials also told the Journal that some items, such as chocolate and books, are dense and can obscure other items when passing through the X-ray.

The US is considering banning laptops from carry-on luggage on all international flights Credit: GETTY

Washington recently had to deny reports from Brussels that an extension of the laptop ban had been scrapped.

An announcement of an extended ban had been considered imminent and was expected following a call between John Kelly, the Homeland Security Secretary, and European Home Affairs Commissioner Dimitris Avramopoulos and Transport Commissioner Violeta Bulc.

Secretary Kelly said in a statement that he will implement "any and all measures necessary to secure commercial aircraft flying to the United States – including prohibiting large electronic devices from the passenger cabin – if the intelligence and threat level warrant it."