However, photos could still be found on other social media sites.

The 150-metre-tall building, located in the eastern extension of the capital's central business district, was designed by Zhou Qi, a professor of architecture at Southeast University in Jiangsu . It is expected to be finished in May 2014.

In a recent interview with the , Zhou explained that his design echoed the ancient Chinese philosophy of "round sky and square earth", with the top part being cylindrical and the rest being squarish.

The elongated spherical form, he explained, was designed to appear from a bird's-eye view as the Chinese character for "people".

"Our [team's] way of expression is kind of extreme, different from the culture of moderation that Chinese people are accustomed to," Zhou said.

Zhou's team won the final design bid for the project in 2009. But it quickly came to the attention of the public after the design plans were published, and many people have poked fun at it.

Some have described the building as looking like a steel-framed penguin, a giant juicer, an electric iron, a chamber pot and even an aircraft carrier. Some have said it looks like "the Gherkin" in London or Dubai's Burj Al Arab, a luxury hotel.

But now that it is under construction, when viewed from a certain angle, some say it very clearly looks like a penis.

Others have joked that the building will compliment the headquarters of China Central Television, completed a few blocks away in 2008, which earned the nickname "the Big Underpants" for their shape.

"How perfectly the two match," one wag wrote on a website. "After five years, CCTV will never feel alone."