A Vietnamese former banking executive was sentenced to death Friday in a massive fraud case, while his co-accused got life in a blockbuster trial involving 51 bankers and businessmen.

The sentences were delivered at the end of a month-long trial as Vietnam's leadership wages an anti-corruption sweep, targeting ex-officials, bankers and executives accused of graft and mismanagement.

Former Ocean Bank general director Nguyen Xuan Son was sentenced to death for embezzlement, abuse of power and economic mismanagement.

Fellow kingpin and ex-Ocean Bank chairman Ha Van Tham, once one of Vietnam's richest men, was jailed for life on the same charges, as well as violating lending rules.

Both men left the courthouse stone-faced after the verdict was handed down.

The trial targeting high-flying executives accused of losses worth millions of dollars has captivated Vietnam.

The charges cascaded down the ranks, targeting accountants, branch managers and scores of others in one of the country's largest-ever banking trials.

The other sentences announced Friday ranged from 22 years in prison to 18-month suspended sentences and re-education outside of prison.

"Tham and Son's behaviour is very serious, infringing on the management of state property and causing public grievances, which requires strict punishment," said judge Truong Viet Toan.

Tham, Ocean Bank's founder, was convicted of illegally approving a $23 million loan in 2012 and economic mismanagement causing major losses.

Also included in the indictment was PetroVietnam's acquisition of a $35-million stake in the bank in 2009. It was later written off.

Son, director of the bank at the time and who later became chairman of the powerful state oil firm PetroVietnam, was sentenced to death for embezzlement, abuse of power and wrongdoing.

The scandal sparked the demise of Ocean Bank.

It had been part of Ocean Group, which takes in real estate and hotel subsidiaries and enjoyed a meteoric rise after its founding in 2007. It was valued at $500 million in 2013 under Tham's stewardship.

Ocean Group is still active in real estate, hotels and services and was valued at $3.5 million in 2016, according to its website.

Vietnam's banking scandal-hit banking sector has long been plagued by dodgy loans and favouritism, which observers say risks hampering the country's solid economic growth.