Row over £1.05m amenities block comes amid growing concern over the cost of the event, which is taking place in Osaka in 2025

Visitors to next year’s world exposition in Japan could find themselves spending a penny in toilets that cost more than £1m to build, with recent construction estimates for restrooms sparking a row over the event’s spiralling costs.

Japanese media reported this week that some of the 40-plus bathrooms being built at the site in Osaka, a port city in the west of the country, will cost as much as ¥200m (£1.05m).