Many thanks for your patience, I am pleased to be able to continue assisting with your query now.
Being placed on suspension is not an automatic indication of guilt and does not amount to formal disciplinary action. Whilst it can be the start of a disciplinary process, it is certainly not a given that it will end up that way.
Suspension is primarily used as a precautionary measure in more serious cases, whilst the employer investigates any allegations against an employee. Reasons for suspending could be in the case of gross misconduct; breakdown of working relationship; risk to an employer's property, their clients or other employees; to preserve evidence or ensure it is not tampered with; avoid potential witnesses being pressured or intimidated, etc.
If the investigation provides enough evidence to justify disciplinary action, the employee has the right to be informed in advance of the allegations and provided with the evidence to be used against them. That will give them the opportunity to prepare a defence for the forthcoming disciplinary hearing. They also have a right to be accompanied by a colleague or trade union representative.
On the other hand, if the investigation does not find enough evidence to justify a disciplinary, the employer should terminate the suspension immediately and allow the employee to return to work as normal, without further action.
So it is possible to suspend the employee whilst an investigation is carried out and until the employer has gathered sufficient evidence to make a decision on whether tis was in fact drink-related, or it had a more plausible explanation. However, that may not happen immediately and the employer may even have to go through a formal disciplinary to officially defend herself before a decision is made.