Yang did not immediately return calls last night.
The citizenship file had been released, following public clamour, the week prior to the election, but heavy redactions - said to protect Yang's privacy - meant it was impossible to see what, if any, disclosures he had made about spy history in China.
The Herald complained to the Ombudsman about these redactions, forcing a rethink at the Department of Internal Affairs.
A spokesman for the Ombudsman's office yesterday afternoon said: "DIA have reconsidered its decision to withhold Dr Yang's answers to the study and work history questions on the citizenship application."
In a press conference after news of his background broke, Yang said he had served as a civilian officer in the PLA and was required to not to name the institutions as a condition of being allowed to leave China.
He said he was not a spy, but conceded he was involved in training spies to assess intercepted communications.
Yang said he instead referred on applications to "partnership" civilian universities who had a relationship with the military institutions. "It is not that I am deliberately trying to cover-up. It's because the system asked me to use the partner university," he said.
At the time Yang denied making false declarations when becoming a citizen - a prerequisite to being able to enter parliament - but said he was reviewing his citizenship application to make sure it was correct.
Yang reentered Parliament at last month's general election, having first been elected in 2011, after securing a placing of 33 on the recent National Party list.
The Financial Times and Newsroom last month broke news of Yang's past and reported the Security Intelligence Service had taken an interest in Yang's background.
The intelligence agency was said to have been conducting interviews with people familiar with his activities as recently as last year. In March of that year, Yang was removed from the foreign affairs, defence and trade parliamentary select committee where he had served since October 2014.
This week the SIS declined again to answer any questions about Yang, citing national security as a reason for withholding information.
"NZSIS does not comment on specific cases or individuals," a spokesman for the spy agency said.
"I can neither confirm nor deny the existence or non-existence of information."
Requests under the OIA to other public agencies who deal with Yang have also been filed by the Herald.
The University of Auckland has refused to release information relating to his appointment in 1999 as a senior lecturer in political science, citing Yang's privacy. This refusal is also the subject to a complaint to the Ombudsman.
Immigration NZ is still considering whether to release information relating to Yang's residency applications, a precursor to his citizenship.
