Sir Brian Leveson has said “challenges and difficulties” remain at Boohoo as the fast fashion giant published his fifth and final report following its supply chain scandal.

The retired judge was appointed to provide oversight for Boohoo’s Agenda For Change programme in late 2020 after Alison Levitt QC found that there were “serious issues” in the company’s supply chain.

It launched the review programme after allegations of ill-treatment of staff at warehouses in Leicester in 2020.

In his previous report, Sir Brian highlighted progress across Boohoo’s work in its supply chain, responsible purchasing practices, sustainability, and ethical compliance as well as modern slavery training programmes.

On Tuesday, the retail group published his latest report, which said that some areas are still a “work in progress” but highlighted significant improvements across Boohoo operations.

Sir Brian said in the report: “I do not pretend that the conclusion of the Agenda For Change programme and its transfer into business as usual represents the completion of each aspect of each recommendation made in the review.

“Many have been completed; others are in progress but still require continued effort to bring to fruition: this is not the least true in respect of the ambitious IT programmes that have been undertaken and are in the process of implementation and in relation to the group’s ambition for Thurmaston Lane as a centre of excellence for garment manufacture in Leicester.

“Furthermore, even if all the recommendations had been completed (or when they are), it cannot be said that it would represent the end of the process.

“I have no doubt that there will continue to be challenges and difficulties along the way and Boohoo must be prepared to demonstrate that, in relation to each aspect of its business, it has exercised due diligence to ensure that legal and ethical standards have been maintained by all both in the business itself or, just as important, in its supply chain.”

Following the review, Boohoo’s suppliers will now require independent approval on their sourcing and ethical compliance, the company said.

The update comes ahead of the company’s final quarter trading announcement on Thursday.

Shares in Boohoo were down 3.1% at 67.4p in early trading on Tuesday – their lowest price since 2016.