A senior Pakistani diplomat has called for an inquiry into allegations that rich landowners diverted water into unprotected villages during the floods to save their own crops.
UN ambassador Abdullah Hussain Haroon said there was evidence that landowners had allowed embankments to burst.
This led to waters flowing away from their land, he said.
More than 1,600 people have died in the floods, which have affected about 17 million people.
"Over the years, one has seen with the lack of floods, those areas normally set aside for floods have come under irrigation of the powerful and rich," Mr Haroon told the BBC's HardTalk programme.
"It is suggested in some areas, those to be protected were allowed, had allowed, levies to be burst on opposite sides to take the water away. If that is happening the government should be enquiring."
At the height of the floods, it is estimated that one-fifth of the country - an area the size of Italy - was underwater.
The flood waters are beginning to drain away to the Arabian Sea but inundations continue in parts of Sindh province.