Compensation to be paid to Kenneth Matiba for unlawful detention has risen to Sh1.8 billion according to new documents file in court.
Matiba's lawyer John Mburu said interest on the Sh945 million awarded to the multiparty democracy hero has accrued to Sh1,458,520.
Matiba was awarded the compensation on August 16, last year.
The court had also given him an additional Sh135 million as the cost of the suit.
The figure has been contested by the government, causing the payment delay.
Matiba, 85, died on April 15 after years of ill health.He died before receiving the award.
The sh1.8 billion sought is inclusive of special and general damages of Sh978,413,040, court documents show.
Interest on special damages have been put at Sh737,362,941.
Taxed cost is stated as Sh135,143,893. The rest is interest on costs from the date of ruling.
Mburu said interest on cost and special and general damages will keep on increasing at court rates until full payment.
Matiba, a former Kiharu MP, suffered stroke on May 26, 1991, but remained in detention without medication for one week.
Justice Isaac Lenaola said Matiba had proven great violations were meted upon him by state agents before he was released on June 4, 1991.
Lenaola, now a judge of the Supreme Court, said the state should bear 20 per cent of the claim Matiba had made for the collapse of his empire.
He held that the politician's businesses deteriorated while others collapsed owing to his absence at their helm.
The court noted that Matiba was fit physically and used to climb mountains but was reduced to "a state of complete inactivity".
The family had said he lost investments worth Sh5 billion in commercial real estate and in privately held shares.