The supermarket giant had argued that store jobs were not comparable to distribution centre jobs.
A report by the Equality and Human Rights Commission, which analysed just 10 pay dispute cases, has been labelled a "whitewash".
The EHRC found no unlawful acts of pay discrimination. It did not investigate the Samira Ahmed case.
Validity of gender pay gap records could be undermined as some 3.2m workers are wiped off.
Ethnicity pay gap continues to plague England and Wales, new data show, with the capital worst affected.
“Because care work was traditionally carried out by women for free, society gives it no monetary value," campaigners say, as calls grow to better their pay and conditions.
The difference between prize money for men and women is stark.
Women at the airline earn 47.9% less than men.
It will examine whether female staff faced unlawful pay discrepancies.
This year, 10 November marks the day when women are essentially 'working for free' thanks to the gender pay gap in the UK. On average, women earn 13.7 percent less than men. Activists are calling for people to speak more openly about their pay checks so that disparities can be raised with their employers.