Tokyo Olympic organisers Wednesday called on the Japanese public to donate old smartphones and other old electronic devices to help make medals for the 2020 Games. In a push to give the Olympics an environmentally friendly hue, Tokyo's organising committee is aiming to collect eight tons of gold, silver and bronze at recycling bins across Japan from April, officials said, to make 5,000 Olympic and Paralympic medals.

Tokyo 2020 said e-waste such as digital cameras, laptops and games units can also be donated at collection boxes in more than 2,000 stores of mobile phone giant and Olympic sponsor NTT Docomo. Recycled metals have been used in previous years to make Olympic medals, including in Rio last year where the silver and bronze medals were 30 percent made from recycled materials.

Organisers insisted they would look to keep costs as low as possible with Tokyo's preparations for the Games plagued by concerns over soaring prices. Experts had warned the total Games budget could hit an eye-watering $30 billion -- four times the initial estimate and almost triple that of the 2012 London Olympics.