The Court ordered Mr Samak's inheritors--his widow, Mrs Surat and daughters Kanchanakorn Chaiyalap and Kandapha Mungthin to jointly pay Bt587 million compensation to the BMA.
The amount was 30 per cent of the Bt1.958 billion the BMA had already paid to Austria’s Steyr Daimler Puch Spezialfahrzeug for the purchase of the fire engines and boats.
They were also ordered to pay 7.5 per-cent interest retroactive to 2004 when the BMA paid the money to the Austrian company.
Mr Samak, then Bangkok governor was accused of malfeasance regarding the fire truck and boat procurement project which cost nearly Bt6.7 billion.
The purchase was later suspended after it was found that the fire vehicles were defective and their prices had been too high.
The Court ordered Mr Pracha to compensate the BMA in the same amount due to his role as deputy interior minister who supervised the BMA at that time.
The compensation must be paid within 60 days of the court verdict.
However, they could still appeal the court's ruling with the Supreme Administrative Court within 30 days.
The case involves the purchase of 315 firefighting trucks and 30 boats at what is alleged to have been inflated prices. Mr Samak was governor at the time of the purchase, but died in 2009.