UPDATE 19/02: Mr Mantach has revealed a shocking lack of oversight that allowed him to funnel money out of the Liberal Party.

"I always expected that this would be caught at some point," Mr Mantach told police, according to court documents.

ORIGINAL: Former state director of the Victorian Liberal Party, Damien Mantach, has pleaded guilty to siphoning close to $1.5 million from party coffers.

Mantach oversaw the Liberal party's 2014 Victorian election defeat before standing down in March last year.

This week, he pleaded guilty to 44 counts of obtaining a financial advantage by deception in Melbourne Magistrates Court.

In court documents allegedly obtained by News Corp reporters, fraud and extortion squad detectives said Mantach transferred $1.44 million of Liberal Party money into an account set up in the name of his wife, between June 2010 and January last year, as well as $82,750 into a joint account.

Mr Mantach was arrested and charged in December last year, after allegations surfaced in August, infuriating the Victorian Liberals. 

At the time, many wondered how Mr Mantach was even appointed to the position, given that he was effectively sacked as Tasmanian Liberal director for spending party money for personal use.

He was forced to pay back close to $48,000 and resign as Tasmanian Liberal director after his theft was revealed back in 2008.