Ever since the footage from the trial of the ousted Chinese leader Bo Xilai's wife was made public, Chinese Internet users have been circulating composite images of Gu's court appearance and those before the trial.
Gu, often referred to as China's Jackie Kennedy, by virtue of her sharp features, looked strikingly different from her image which was captured during the trial.
"Are we looking at the same woman? There are rumors that the woman who appeared in the court room is a body double, because whether you are thin or fat, your bone structure shouldn't change," BBC quoted a Chinese Internet user.
"Please note the corner of the mouth, the bags under the eyes and the ears, especially the ears. You might flatten the bags, but you can't change the shape of your ears," another user wrote.
In a pre-trial article published Aug. 18, the Financial Times cited two security experts familiar with facial recognition software who said that "the person shown in state television footage of the courtroom was not Gu."
China's largest Internet search engine Baidu and microblogging service Sina Weibo have both blocked the Chinese term for "body double" or "body replacement" amid rising speculation. The term "Zhao Tianyun" has also been blocked following claims that Gu Kailai's impostor was a "46-year-old Langfang resident Zhao Tianyun."
"A lack of legal transparency has opened space for skepticism, particularly in a society in which elites are often exempt from laws or are able to wiggle out of harsh punishments in ways not available to ordinary citizens," the Wall Street Journal said in an article that sought to examine the merits of the claim that Gu used a stand-in.
The report said Gu's weight gain, believed to have been due to her "certain degree of dependence" on mood-altering drugs, may have significantly changed her physical appearance.
This is not the first time a high-profile defendant has been accused of using a body double during a judicial trial.
In 2009, it was alleged that the son of a wealthy businessman, who ran over and killed a young man, had used a stand-in at his trial, AFP reported.