CHISINAU- The investigation of a stolen $1 billion from Moldovan banks more than a decade ago should continue after the conviction of a prominent business magnate, the speaker of the country's parliament said on Saturday.

A court sentenced businessman Vladimir Plahotniuc, one of Moldova's richest men, to 19 years in prison this week in a case dubbed the "theft of the century" involving the transfer abroad of a sum equivalent at the time to 12% of Moldova's gross domestic product. The money was siphoned out through dubious loans, asset swaps and shareholder deals.

He was personally accused of receiving payments of $39 million and 3.5 million euros ($4.1 million) from three banks. Prosecutors had sought a 25-year sentence.

Igor Grosu, the second-ranking person in Moldova's state hierarchy, told reporters that further investigation was vital to discovering the whole truth behind the mass fraud, as Plahotniuc could not have been solely responsible.

"The scale of the investigation shows that Plahotniuc could not have acted alone. He could not have organised, on his own, all the actions, operations and transactions," Grosu said.

"This is all quite sophisticated, all the more so as one of the accusations against him was organising a criminal group. I don't know what other action is being taken by prosecutors, but I believe it is logical to look into episodes involving other persons, including those who insisted he was innocent."

Plahotniuc denied the charges. His lawyer, Lucian Rogac, said the case violated the legal process and alleged the verdict was subject to public pressure and political interests.

Anti-corruption prosecutors are pursuing three more cases against Plahotniuc concerning involvement in a criminal group, allegations of bribery and the creation of monopoly conditions in the export of metals.

Plahotniuc, 60, headed Moldova's Democratic Party from 2016 to 2019, part of the governing coalition at the time, and served as deputy speaker of parliament. While in office, he wielded great influence over the police, judiciary and courts.

(Reporting by Alexander Tanas, writing by Ron Popeski, editing by Rod Nickel)