More than 100 current and recent UK staff at outlets of McDonald's have alleged a toxic culture of sexual assault, harassment, racism and bullying at the fast-food chain.

The BBC began investigating working conditions at McDonald's in February, after the company signed a legally binding agreement with the Equality and Human Rights Commission (EHRC) in which it pledged to protect its staff from sexual harassment.

The BBC was told that workers, some as young as 17, are being groped and harassed almost routinely. The UK equality watchdog said it was ‘concerned’ by the BBC's findings and is launching a new email hotline.

Over a five-month period, The BBC reached out to McDonald's workers to ask about their experiences of working there. Of the more than 100 allegations from employees it spoke to, 31 related to sexual assault, and 78 related to sexual harassment. It also heard 18 allegations of racism, while six people made allegations of homophobia.

McDonald's said it had ‘fallen short’ and it ‘deeply apologised and added that all employees deserved to work in a safe, respectful and inclusive workplace.

Multiple workers told the BBC that McDonald's managers at the outlets across the UK were responsible for the harassment and assaults. Senior managers were said to have failed to act on complaints.

Allegations of sexual harassment at McDonald's first surfaced in the UK five years ago when the Bakers, Food and Allied Workers Union (BFAWU) said it received 1,000 complaints. There was very little reporting of the allegations at the time, the BBC said this could be because some cases were settled using confidentiality clauses.

Sarah Woolley, BFAWU's general secretary, said the new allegations uncovered by the BBC were "shocking".

Alistair Macrow, chief executive of McDonald's UK & Ireland, said there was "simply no place for harassment, abuse, or discrimination" at the company.

“Every one of the 177,000 employees in McDonald's UK deserves to work in a safe, respectful and inclusive workplace. There are clearly instances where we have fallen short and for that we deeply apologise," he told the BBC. "We will investigate all allegations brought to us, and all proven breaches of our code of conduct will be met with the most severe measures we can legally impose, up to and including dismissal."

Macrow added that more than 2,000 managers had completed full awareness training and that most restaurant teams were now working within the new protections which aim to create ‘a safe and respectful workplace’. Macrow also said the company has stringent rules to ensure its workplaces around the world are safe and respectful.