Papers have been sent to prosecutors on a Tokyo rental firm manager who allegedly allowed foreign tourists to drive go-karts on the street without a valid license.

Tokyo police say the person in their 40s is suspected of renting small racing cars to two foreign tourists without a valid international permit to drive on public roads in April. Police say the tourists did not have driving licenses issued under the Geneva Convention on Road Traffic.

The manager is accused of violating Japan's Road Traffic Act.

Police say the case surfaced after a kart collided into a parked vehicle near a crossing in Tokyo's Minato Ward.

Street go-karting is popular among foreign tourists.

The company started a kart rental business around autumn last year. Police suspect the firm has rented karts to about 50 foreigners without effective permits.

The manager has reportedly told investigators that staff checked whether customers had international driving permits, but failed to confirm they were issued by countries party to the Geneva Convention.

Tokyo police say traffic accidents involving small motor-racing vehicles have been rising sharply. This year, the number reached 25 by the end of August. That's a significant increase from a total of 12 last year.

Police also received 134 emergency calls concerning karts by the end of August. Many were said to be complaints. One said that the driver was using a smartphone while driving. Another said that a group of karts were parked in the street.