In October Simon Ostrovsky's report revealed how many of the UK's top High Street stores were selling clothes made with Uzbek cotton.
His investigation of cotton production in Uzbekistan found that the use of children to harvest the crop was widespread and systematic.
Tesco said the Newsnight report had "exposed the continued use of state-sponsored child labour in Uzbek cotton fields" and has now announced a complete ban on the use of Uzbek cotton.
The retail giant is telling suppliers that "the use of organised and forced child labour is completely unacceptable and leads us to conclude that whilst these practices persist in Uzbekistan we cannot support the use of cotton from Uzbekistan in our textiles".
Later in the fields in the north the reality of cotton production in Uzbekistan is laid bare.
Even though it is September, the cotton fields are full of school children hard at work.
One boy said that the children have been sent to pick cotton. He said he wouldn't return to school until November - when the cotton harvest was finished.
Human rights groups estimate some 450,000 children like him are shut out of schools and working in the cotton fields of Uzbekistan every harvest.
Another child, a nine-year-old girl who has to work from eight in the morning until sunset, said: "They have closed the school - that's why I'm picking cotton."
Later police are seen marshalling hundreds of children onto buses bound for the cotton fields.
A row of trucks next to the buses is filled with bedding and mattresses that the children will sleep on once they get to the fields.
The convoy gets its own police escort.
During filming the Newsnight team are arrested but manage to hide the footage from police.