Former prime minister Najib Abdul Razak and his son Mohd Nazifuddin failed to quash a High Court ruling in relation to the tax suits against them.

The Court of Appeal today dismissed the appeals by the father and son to nullify the summary judgment issued against the duo in their respective RM1.69 billion and RM37.6 million tax suits.

Under civil law, a court may allow summary judgment, which entails...