From the BBC news item:

…Conrad Chau altered prescriptions to get pharmaceutical firms to send him more drugs at a discounted price so he could sell them on to other companies at a profit.

The offences took place in 2013 while he was owner of the Holburn Pharmacy.

{snip}

The fraud was discovered when a comparison was made between the genuine prescriptions issued by local GPs and received by the NHS, and the forged versions of the same documents, which had been sent to the pharmaceutical companies.

Read more at the link:
http://www.bbc.com/news/uk-scotland-north-east-orkney-shetland-40729546