Uber has come under fire in many countries over licensing issues. In the latest developments, China has banned taxi apps from using cars and drivers without taxi licenses and Germany's highest court has declined to hear a complaint brought by the online taxi service over a ban on its activity in the city of Hamburg. China's transport ministry has banned taxi apps such as Uber and local rivals Kuaidi Dache and Didi Dache from using cars and drivers without taxi licenses in a bid to regulate the sector.

Previously, authorities in the Chinese city of Chongqing had began investigating Uber in December over concerns that its drivers were not properly licensed.

Uber, backed by Chinese internet giant Baidu and also Goldman Sachs and Google, charges a fee to play matchmaker between passengers and drivers, some of whom are registered taxi drivers.

The company argues its service does involve professional drivers but rather private persons who did not require a special license.

In Germany, the Federal Constitutional Court said the declined to hear a complaint brought Uber over a ban on its activity in the city of Hamburg, "due to lack of admissibility."

Hamburg's transport office sent Uber an injunction in July last year that said its drivers needed special licences to transport passengers.