(Reuters) - Staff at Sports Direct International Plc, afraid they would be fired for taking sick leave, made more than 80 calls to ambulances from the British company's headquarters over a two-year period, the BBC reported on Monday.

The BBC reported that three of the calls made between January 2013 and December 2014 involved women with pregnancy difficulties, including one who gave birth in toilets at the Shirebrook site in central England. (http://bbc.in/1WGRtOP)

Sports Direct, Britain's biggest sporting goods retailer, said "key identifiable allegations" in the BBC report were unfounded.

The company did not specify these allegations but said that some of the allegations in the BBC's Inside Out program could not be investigated because they had been made anonymously.

"Sports Direct aims to provide working conditions in compliance with applicable employment and health and safety legislation and seeks to provide safe working conditions for all staff working in our warehouse," the company said in a statement emailed to Reuters.

The BBC said it had obtained details of the ambulance callouts by making a Freedom of Information request to East Midlands Ambulance Service.

Asked to comment on Sports Direct's response, the BBC said: "This is a balanced documentary which includes hard evidence to support the points being made as well as a right of reply from Sports Direct, so we stand by our journalism."

The BBC quoted a document produced by an agency that supplies staff to Sports Direct, which said any person exceeding six unscheduled sick leaves within a rolling six-month period would have their assignment ended.

Sports Direct said the two agencies that employ warehouse staff at its Shirebrook site operated a "performance strike" system that takes into account an employee's timekeeping, attendance, sickness, conduct and performance target levels.

"When a member of staff falls below the required standards, the reasons for this will be discussed (including any mitigation) and support and training will be provided to help the individual reach the targets expected of them," the company said.

Sports Direct also said it took extra precautions with pregnant women, which would include calling an ambulance if there were concerns for the wellbeing of a mother-to-be or her baby.