At the same time he pleaded to those counts, he was discharged by Justice Murray Gilbert on five charges of dishonestly using a document. The bankrupt accountant could now face further jail time on top of the three years and seven months in prison he was given this year in a different case.
Williams' offending took place between mid-2003 and 2007 at Five Star Consumer Finance, one of the companies in the collapsed Five Star Group.
FSCF failed in August 2007 owing $54.4 million, of which $12.2 million has been recovered.
Other companies in the group, including Five Star Finance, collapsed owing more than $40 million, little of which has been recovered.
The charges Williams admitted to yesterday were associated with about $43 million of related party lending, in breach of FSCF's trust deed - the document with the rules dictating how investor funds can be used.
Williams' lawyer Sam Wimsett said the guilty plea was the elderly bankrupt "taking responsibility for some of the unlawful activity" that took place at Five Star.
"I think one of the problems was that he'd been painted as overall architect or the big boss and he's had a problem with that. I think he's now been prepared to [take] responsibility for what his role was," Wimsett said.
However, Wimsett said he could not reveal too much before sentencing about what Williams claimed his role at the companies actually was.
One witness in the High Court this week described Williams as a "puppeteer" and said he "controlled a lot of what was happening at Five Star".
An investor in the failed group, Joe Tregerthan, told the Herald yesterday that the guilty plea at least would "save the government a few bucks".
"But a lot of investors especially in Five Star Debenture Nominee, they're still suffering. Some of them haven't had a payout and a lot of those people are very elderly and some are quite sick," Tregerthan said.
"The big question that people still want to know [the answer to] is 'where is the money?'."