Sky Sports F1 pundit Craig Slater revealed during testing that the investigation would be finished by 'Monday or Tuesday', and Sky Sports have now reported that it has been completed.
When will Horner's investigation be completed?
The result of the investigation will be released before the start of the Bahrain Grand Prix weekend, with an announcement expected later on Tuesday or on Wednesday.
Sky Sports say that the Red Bull GmbH board are now in possession of an extensive 100-page document given to them by a specialist barrister.
They report that confidentiality laws are likely to limit the amount of information shared publicly, but that the findings will be the result of a 'thorough and fair investigation'.