After speaking to many practitioners most of the people seemed to be surprised by the recent high sanctions on UK business visa holders that are found to actually doing work. If someone is caught intending to or actually performing unauthorized work in the UK they could be barred from reentry for 10 years. Moreover criminal sanctions can brought against the HR individuals involved the company may face a fine of 10000 pounds per illegal worker and the company's license may be revoked, leading to all workers on that license being out of status.