The firm KYB and its subsidiary have admitted systematically doctoring data for hydraulic oil dampers aimed at reducing shaking during earthquakes.

Among the venues for Tokyo 2020 they are involved in building are the Olympics Aquatics Center and the Ariake Arena, due to stage volleyball during the Games.

The Tokyo Skytree Tower, expected to be one of the most recognisable landmarks in the Japanese capital during the Olympic and Paralympic Games, is another building using KYB products.

In July 2017, the Japanese Government estimated that there is a 70 per cent chance of a magnitude 7-class earthquake hitting directly beneath the Tokyo Metropolitan area within 30 years.

KYB have claimed there is no immediate danger but they have been heavily criticised by Tokyo Mayor Ichirō Matsui after it was revealed they had manipulated data between 2003 and September last year. 

"It shows a decline in corporate ethics," he told Japanese press agency Kyodo News. 

"I want [the company] to recognise that data falsification could put people's lives at risk."

Japan's Infrastructure Ministry claimed there was no risk that the affected buildings could collapse, even if they are hit by an earthquake at the top of Japan's seismic intensity scale.

It plans to order 88 makers of quake absorption devices in the country and report by year-end whether similar misconduct occurred.

An External Commission is being set-up by the Japanese Government to explore the problem, while KYB has promised it will replace the affected devices.

The scandal is the latest controversy to hit Japan after several leading companies admitted they had falsified safety data.

Last year, Kobe Steel admitted it tampered with quality data of products delivered to major companies, including Boeing and Toyota.

In July, Nissan admitted it repeatedly falsified data on exhaust emission control and fuel economy.