A boss in Norway has ordered all female staff to wear red bracelets during their periods - to explain why they are using the toilet more often.

The astonishing demand was revealed in report by a workers' union into 'tyrannical' toilet rules in Norwegian companies.  

The study claimed businesses were becoming obsessed with lost productivity due to employees spending too much time answering the call of nature

It found 66 per cent of managers made staff ask them for an electronic key card to gain access to the toilets so they could monitor breaks.

Toilets in one in three companies were placed under video-surveillance, while other firms made staff sign a toilet 'visitors book', the report by the Parat union said.

It added: '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.' 

The report, which did not name the firm imposing red bracelets on female staff, has now been passed on to Norway's chief comsuner ombudsman Bjorn Erik Thon.

He said: 'These are extreme cases of workplace monitoring, but they are real.

'Toilet Codes relating to mentrual 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.

'We receive many complaints about monitopring in the workplace, which is becoming a growing problem as it is so often being used for something other than what it was originally intended for.

'We will be carrying out a full review of the rules surrounding employment and privacy over the coming year.'