Gross misconduct

the employer should:-

Make a reasonable decision as to the severity of the offence in order to make absolutely sure that the breach, if proved, would warrant summary dismissal without notice or pay. If the employer decides that the severity is not apparent, then he should not dismiss, but take action in accordance with the degree of seriousness determined.

Fully investigate and record the background to the offence, taking witness statements if possible, then arrange a disciplinary hearing, giving the employee the right to be represented and the opportunity to explain his or her side of the case. Allow the employee to question witnesses or witness statements, and the events must be fully recorded.
The employer should then make a reasonable decision on the evidence presented, taking into account the employee's service, position and record with the organisation, and bearing in mind any decisions made in respect of other employees in similar situations.

Communicate the decision in writing to the employee and allow the right of appeal as outlined for Misconduct and Serious Misconduct.