KUALA LUMPUR (THE STAR/ASIA NEWS NETWORK) - Tax-related cases by former Malaysian prime minister Najib Razak and his two sons involving a total of RM1.74 billion (S$570 million) in arrears will be up for case management at the Court of Appeal on Dec 16.

A check on the online e-filing system showed that the three separate cases of Najib and his sons - Datuk Mohd Nizar, 42, and Datuk Mohd Nazifuddin, 35 - would be brought before deputy registrar Mohd Khairi Haron via e-review on the same day.

Najib, 67, is appealing against a High Court decision that allowed a summary judgment by the Inland Revenue Board (LHDN) against him, compelling Najib to pay an additional income tax totalling RM1.69 billion for the period between 2011 and 2017 to the government.

A summary judgment is when a court makes its decision without going to a full trial.

High Court judge Justice Ahmad Bache, in his ruling said there were no triable issues to warrant a full trial in Najib's case.

"Consequently, the court has no alternative but to enter a summary judgment against the defendant for the amount claimed by the plaintiff, " he said.

On June 25 last year, the government through LHDN filed suit against Najib seeking payment for a total of RM1,692,872,924.83, with 5 per cent interest a year from the date of judgment, as well as costs and other relief deemed fit by the court.

It also said Najib was given 60 days to pay the taxes but had failed to do so.

Meanwhile, Najib's sons are also appealing in their respective cases.

On Sept 25, the Shah Alam High Court ordered Mr Nizar to pay RM13.16 million in unpaid taxes from 2011 to the tax department.

In her 14-page judgment, Judicial Commissioner Julie Lack Abdullah ruled that there were no triable issues since the board's claim against Mr Nizar is not time barred.

She added that it is settled law that a person who owes taxes must first pay up before appealing to the Special Commissioners of Income Tax (SCIT).

JC Julie also adopted Justice Ahmad's judgment in the decision to enter a summary judgment against Nizar.

On July 6, Kuala Lumpur High Court judge Justice Ahmad Zaidi Ibrahim entered a summary judgment against Mr Nazifuddin for owing taxes amounting to RM37.6 million between 2011 and 2017, compelling him to pay the amount to the LHDN.