The National Crime Agency and the workplace safety watchdog visited factories and businesses across Leicester on Friday as they sought to address concerns that inadequate standards at garment manufacturers played a role in the city’s second wave of coronavirus. The Health and Safety Executive visited 11 premises, in some cases alongside officials from Leicestershire police, the NCA and other agencies. An HSE spokesperson said the activity was “focused on the textile industry” in the city. Police said they made “routine visits” to nine factories and workplaces, adding that no enforcement was carried out but advice was given on health and safety issues. One person was detained in relation to immigration matters. The HSE spokesperson said: “No notices were served and no businesses were shut down. However, verbal advice was given to all of them and further inquiries are being made with a number of the businesses to ensure compliance with safer workplaces guidance.” The visits appeared to have been carried out as part of new scrutiny of the textile industry in Leicester following allegations that factories may have failed to ensure their workforces were protected from Covid-19 at the beginning of lockdown. Earlier this week, a report by campaign group Labour Behind the Label revealed testimony from garment industry workers who claimed that some people had been forced to work despite having symptoms of the virus. Public Health England said on Thursday it had found “no explanatory outbreaks … in industrial processes”, an apparent reference to factories. But PHE analysis of data collected by local health bodies had previously shown that many of those infected recently have been young men aged 20 to 40, often from an Asian background, many of them working in textiles or food. HSE had already begun investigations into three textile businesses in the city, and said on Wednesday that it was taking enforcement action at one site. The heavy scrutiny of the garment factories and associated businesses in Leicester appear to have provoked anxiety in the industry, and leading figures are understood to have held a meeting on Friday night to discuss their response to the situation. Separately on Friday, an industry source provided the Guardian with a list of more than a dozen suppliers that they alleged sold to the fast fashion brand Boohoo and continued to operate during the crisis despite infected workers being on site. Two community sources who were consulted about the list said it was corroborated by information from whistleblowers. Boohoo previously said none of its suppliers had been affected. On Friday, it did not respond directly to the claims when asked for comment by the Guardian, but said it was “working with our third-party compliance partner to further investigate the claims raised and are working with suppliers to ensure compliance”. It has previously said its head office was “in constant contact with our suppliers” via video and audio calls during the early weeks of lockdown when compliance visits were impossible and that it had subsequently resumed on-site auditing. A number of other explanations have been put forward as possible factors in Leicester’s surge in coronavirus cases, ranging from the failure of central government to share data with local authorities to overcrowded housing.