He said he had never heard of a Member of Parliament seeking to involve themselves in vetting decisions and demanded answers.
"These are serious allegations that need to be investigated," he said.
Yang has become a lightning rod for domestic and international debate about China's increasing influence after the Financial Times and Newsroom revealed his background prior to becoming a New Zealand citizen and MP included at least 15 years working with China's military Intelligence apparatus.
National Party leader Bill English said he had not discussed today's Herald report with Yang, but defended his MP's handling of the episode.
"He's dealt with a concern from a constituent in a way that any MP is virtually obliged to. I think it's overstretching it to say that he tried to overturn a security classification," he said.
Prime Minister Jacinda Ardern declined to comment on individual national security cases, but backed comments last night from minister for intelligence services Andrew Little.
"As a general statement, it's inappropriate for MPs to lobby around security clearances," she said.