The Toyota Prius has reached three million global sales, confirming its status as one of the world's best-selling cars.

In its progress through three generations, Prius has benefited from significant improvements. Its official CO2 emissions figures have fallen from 114 to 89g/km and the cost of its hybrid powertrain has been reduced by two thirds.

In the past two years Prius has grown from being a single model to embrace a family of vehicles designed and engineered to meet the needs of a wider customer base.

In Europe these include Prius+, the world's first full hybrid seven-seat MPV, and Prius Plug-in, the first Toyota to embrace rechargeable lithium-ion battery technology for extended zero-emissions electric power capability.

In North America and other world markets, the smaller Prius c/Toyota Aqua has also been launched - bringing hybrid to a market segment that's covered in Europe by Yaris Hybrid.

Toyota has made hybrid a core technology for the developing more environmentally efficient vehicles and it continues to make significant investments that will help secure sustainable global growth.

In the financial year ending in March 2014, it is expected to spend more than £5bn on research and development and facilities for developing hybrid and other cutting edge technologies, as well as strengthening development of new platforms and components.