When asked on BBC Radio if he thought Fujitsu could face a bill of "hundreds of millions of pounds" to compensate victims, Hollinrake said: "Yes, I do."
"This will cost the taxpayer a billion pounds, maybe more than that," he said, adding that he "absolutely" thought the Tokyo-listed company should contribute a significant proportion of the redress cost.
The IT group's European head Paul Patterson last week told a parliamentary panel that the company had a "moral obligation" to compensate the hundreds of Post Office workers who were wrongly convicted of fraud, theft and false accounting between 1999 and 2015.
The recent airing of a TV drama on the scandal, which arose as a result of Fujitsu's faulty Horizon software, has rekindled public interest in the matter.
Prime Minister Rishi Sunak called it one of the country's biggest miscarriages of justice and has set out plans to mass exonerate those convicted.
(Reporting by William James and Muvija M; editing by Sarah Young)
