Chris,
Problem was sorted on Tuesday, somebody had turned the stop tap off in the wall cabinet, either in error, as a joke or possibily to encourage somebody out of the flat perhaps while the door was left open, I don't know.
My neighbour had tried to check the locked cabinet which is TV/phone cabinet next to lift but eventually understood what I meant by the cupboard at the top at the stairs round the corner from the lift.
The problem may also have been because the left tap is for he right flat and visa versa in the cupboard and so the owners of the other flat if its sold may have turned the wrong one off.
For 2 days they had to use water from the tap in the garage.