After an audit, officials discovered that $590 million figure was actually $757 million.
The total deficit now stands at $1.25 billion, according to officials.
During Question Time today, Clark again blamed the previous National government for the DHB woes and the even wider deficit.
"I make no apology for cleaning up the mess I inherited with the historical underpayment of staff."
But National's health spokesman Michael Woodhouse said when National was in Government, its ministers had asked officials on multiple occasions if there were potential breaches in the Holidays Act and they had said no.
He said Clark became aware of the Holidays Act issues after he was sworn in as a minister in 2017.
The revelation of the widened deficit comes after the Herald this morning revealed that the amount of bailout money the Government has paid to financially struggling DHBs was close to $400m.
The Association of Salaried Medical Specialists executive director Ian Powell said these emergency cash injections for DHBs were a symptom of a "woefully inadequate budget planning process that is increasingly an exercise in futility".
"DHBs are being pressured to find mythical savings that are then not realised. It is a wasteful and futile exercise in wishful thinking."
He called on Clark to show leadership and encourage the Ministry of Health to face reality.
"He [Clark] must ensure that health funding in next year's Budget meets the estimated operational costs of district health boards providing quality care to their patients."