Major high street fashion brands have paid factories in Bangladesh less than the cost of producing their clothes, researchers claim.

A survey of 1,000 factories found many were paid the same prices as before the pandemic two years ago – despite soaring costs of materials. One in five said they struggled to pay Bangladesh’s £2.30 a day minimum wage.

Aberdeen University’s Business School carried out the research alongside justice charity Transform Trade.The report looked at the period from March 2020 to December 2021.

It found 90% of larger high street brands buying from four or more factories were reported as engaging in unfair purchasing practices.

Several retailers denied the claims made in the report.

Muhammad Azizul Islam, professor of sustainability accounting and transparency at Aberdeen University, led the project .

He said: “Two years on from the start of the pandemic, Bangladeshi garment workers were not being paid enough to live on, with one in five manufacturers struggling to pay minimum wage while many fashion brands which use Bangladeshi labour increased their profits.

“Inflation rates soaring around the world are likely to have exacerbated this even further.”

He said larger brands buying from many factories were engaging in unfair purchasing practices more frequently than smaller brands, according to suppliers.

The study also found that after the pandemic, factories only employed 75% of the workers they had before, suggesting that up to 900,000 could have lost their jobs.

Prof Islam has spent 17 years looking into the lives of workers in Bangladeshi fashion factories. He grew up in Dhaka city surrounded by them.

He hopes that policy makers in the UK will listen to his findings.