China has started using anal swabs to test people who are believed to be at a high risk of having COVID-19.
The new method was rolled out last week for residents of neighbourhoods with confirmed cases and those in quarantine facilities, according to state media.
The test only takes around 10 seconds and involves a saline-soaked cotton swab being inserted 3-5cm into the rectum and rotated several times.
The swab is then removed and securely placed in a test container. The sample is then tested for traces of the virus.
While some Chinese doctors claim the method is more accurate than throat swabs, others say the invasive nature of the test is a step too far, according to The Washington Post.
Director of the respiratory disease department of Beijing You An Hospital Li Tongzeng said the new testing was introduced after research showed traces of the virus remain in the anus longer than the respiratory tract.
"If we add anal swab testing, it can raise our rate of identifying infected patients," Tongzeng said per the Washington Post.
"But of course considering that collecting anal swabs is not as convenient as throat swabs, at the moment only key groups such as those in quarantine receive both."
The testing comes as China struggles to contain rising infections ahead of the Lunar New Year celebrations.
The celebrations are often called the world's largest annual migration with around three billion trips made over the holiday in a regular year.
As a result, officials have been tightening restrictions in recent weeks in an effort to stop the virus spreading.
China is also seeking to vaccinate at least 50 million people before the holiday but that is only 4 percent of the population, much below the necessary level to prevent large scale transmission.