More than a million people in Japan have been told to cut back on showers and laundry to help rescuers reach a pensioner stuck in a massive sinkhole.

The 74-year-old and his lorry were swallowed by the sinkhole when it first appeared in Yashio city, just north of Tokyo, on Tuesday morning.

Rescue efforts have been hampered by further collapses with the cavity now stretching to 40 metres (150ft) across, almost the length of an Olympic swimming pool.

The regional government has urged 1.2 million people across 12 towns and cities to refrain from taking showers and doing laundry to temper the strain of leaking wastewater and sewage. 

“Using toilets is difficult to refrain from, but we are asking to use less water as much as possible,” an official said, adding that some sewage was being diverted to a nearby river.

Authorities believe the widening sinkhole could be the result of corroded sewage pipes.