The former head of security and intelligence, Gregorio Leao; the head of the security service's economic intelligence division, Antonio do Rosario; and ex-president Armando Guebuza's son Ndambi Guebuza were among 19 defendants accused in the country's biggest graft scandal.
Guebuza was convicted for embezzlement, money laundering and criminal association, among other charges, while Leao and do Rosario were found guilty of embezzlement and abuse of power.
Eight other defendants were acquitted while the rest were handed terms ranging between 10 and 12 years in a verdict that took the judge a week to read out.
The scandal arose after state-owned companies in the impoverished country illicitly borrowed $2 billion (1.9 billion euros) in 2013 and 2014 from international banks to buy a tuna-fishing fleet and surveillance vessels.
The government masked the loans from parliament and the public.
When the "hidden debt" finally surfaced in 2016, the International Monetary Fund (IMF) and other donors cut off financial support, triggering a sovereign debt default and currency collapse.
An independent audit found $500 million of the loans had been diverted. The money remains unaccounted for.
"The crimes committed have brought consequences whose effects will last for generations," said Judge Efigenio Baptista, addressing a packed courtroom located in the grounds of a high-security jail in the capital Maputo.
Baptista listed some of the assets acquired by Guebuza's son using the $33-million bribe he allegedly received.
They included luxury cars and a 10-million rand ($590,000) mansion in neighboring South Africa.
The debt scandal sparked legal cases across three continents and exposed corruption on a global scale. Swiss bank Credit Suisse was fined $475 million last year over its part in issuing the loans.
Former finance minister Manuel Chang - who signed off the loans - has been held in South Africa since 2018, pending extradition to the US for allegedly using the US financial system to carry out the fraudulent scheme.