Johal had appealed against a court judgment that it had acted unlawfully by paying an illegal immigrant £40,000 to steal confidential customer invoices from JN Dairies. The Court of Appeal rejected claims by Johal that JN and its witnesses were lying and that the trial judge had been biased against them.
The judges said Johal's complaints were without substance and that "no complaint can justifiably be made".
Johal must now pay its own costs and those of JN Dairies for both cases, which could be between £1m and £2m.
The two parties will also return to the High Court later in the year to determine whether damages should be paid to JN Dairies, with Johal expected to argue that there is no legal basis for such a claim.