McDonald's UK boss says fast-food chain faces weekly sex abuse claims, Source: AFP

Alistair Macrow, chief executive of McDonald's UK and Ireland, told a watchdog parliamentary committee that the chain's management also receives around five reports a week of bullying.

He said that his employees' accounts of alleged harassment and racism were "truly horrific and hard to listen to".

It follows the BBC reporting in July numerous allegations of sexual misconduct, racism and bullying by staff at McDonald's outlets in Britain.

The company says it has dismissed 18 employees and taken 75 disciplinary measures, after examining 157 reported cases, since the scandal emerged.

Some 249 cases remain to be investigated, it has said.

Law firm Leigh Day recently launched group legal action against McDonald's after the BBC aired the accusations, which included employees' claims they were "groped and harassed almost routinely".

McDonald's UK opened a specialist unit to investigate the allegations, which stemmed from the accounts of around 100 staff, according to the British broadcaster.

Appearing before lawmakers in parliament, Macrow reiterated that he was "absolutely determined to root out any of these behaviours".

He pledged to identify individuals who are responsible for them and "make sure they are eradicated from our business".

But earlier in the hearing, union leaders claimed that, contrary to those assertions, the situation had not improved within McDonald's since it launched its internal probes.

The unions also claim that the firm has a history of using out-of-court settlements in response to such allegations, including non-disclosure agreements (NDAs).

The Bakers, Food and Allied Workers Union alleged four years ago that more than 1,000 female employees of the fast-food giant were victims of sexual harassment and abuse.

This year's BBC investigation revealed that many female employees under the age of 18 reported being sexually or emotionally harassed.

One ex-employee, Shelby, who was only 16 when she started working at McDonald's, told the broadcaster that she was constantly touched in an inappropriate and unwanted ways by older male employees in the kitchen.

The fast-food chain has 177,000 employees in the UK, many of whom are young workers, including teenagers.