Uber Technologies Inc., the popular taxi service that has courted plenty of controversies, is looking to invest over $1 billion in China.

Why China? Because it's currently the second biggest economy in the world, and investing in China will aid Uber in propelling its growth in the country.

Uber is looking to invest aggressively in China, calling it the company's "number one priority." Taxi service accounts for over a million trips in the country each day, and the company's business has also reportedly "doubled in the last month."

News of Uber's potential Chinese investments comes courtesy of an email that the company's CEO Travis Kalanick supposedly sent to investors.

In the letter, Kalanick revealed that Uber was eyeing a bullish attitude for the Chinese market even though it was faced with office raids and controversies surrounding its drivers who were believed to have been operating unlawfully.

"Since our launch in February 2014, we have found a public that is embracing Uber far beyond our most bullish expectations," wrote Kalanick in the letter to investors.

Kalanick mentioned the speedy growth of the company in Chinese cities when compared to New York.

The CEO also said that Uber intends to launch the cab service in 50 additional cities in China in 2016. Uber currently operates in 11 cities in China, which includes the capital Beijing. The potential for growth in the region was immense as it was an "untapped" market.

"To put it frankly, China represents one of the largest untapped opportunities for Uber, potentially larger than the U.S.," noted Kalanick.

However, he was not overzealous and mentioned that the company's success in the Chinese market, which was loaded with promise, would depend on Uber's long-term commitment, determination, as well as an in-depth understanding of the differences that exist in the Chinese market.

Kalanick, however, seemed optimistic of Uber's success and noted that the company was enjoying a level of success that several tech companies from the U.S. have not. This was attributed to Uber's "organic approach" to the market.

For those wondering about the authenticity of the letter, an Uber executive has confirmed to Reuters that it was genuine.