Raphael Kasambara was sentenced for his role in the attempted murder of ex-National Budget Director Paul Mphwiyo.
Mr Mphwiyo’s shooting in 2013 is believed to have exposed Malawi’s worst financial scandal, known as “cashgate”.
Up to $250m (£150m) was estimated to have been lost in the fraud.
The money was lost through allegedly fraudulent payments to businessmen for services that never materialised.
The systematic plundering of public resources occurred between 2012 and 2014 during the administration of then-President Joyce Banda,
Malawi’s donors then withheld $150m following the scandal’s disclosure.
Kasambara suggested after his conviction last month that he would appeal the verdict.
Mr Mphwiyo, who was the budget director in the finance ministry, was flown to South Africa for medical treatment after he was shot.
He recovered and testified at Kasambara’s trial.