Women staff in offices in Norway have been asked to wear red bracelets when they are on their periods - so that no one would inquire why they were using the toilet more often, a media report in London has said.
This "astonishing demand" was revealed in report by a workers' union into "tyrannical" toilet rules in Norwegian companies.
The study said that businesses were becoming "obsessed" with lost productivity due to employees spending too much time answering the call of nature, the Daily Mail reported.
It found 66% of managers made staff ask them for an electronic card to gain access to toilets.
Toilets of one in three companies were placed under video surveillance, while other firms made staff sign a toilet "visitors book", the union report said.
"But the most extreme action was taken by one manager who made women having their period wear a red bracelet to justify more frequent trips to the loo. Women, quite justifiably, feel humiliated by being tagged in this way, so that all their colleagues are aware of this intimate detail of their private life," it said.
The report, which did not name the firm imposing red bracelets on women staff, has now been passed on to Norway's chief consumer ombudsman Bjorn Erik Thon.
"These are extreme cases of workplace monitoring, but they are real. Toilet Codes relating to menstrual cycles are clear violations of privacy and is very insulting to the people concerned. I hope and believe that this is not representative of the Norwegian working life in general," Thon said.