Blogger Cameron Slater claimed on more than one occasion that his friend and former Cabinet minister Judith Collins was out to have the Serious Fraud Office director sacked, according to a new email.
But statements he attributed to Ms Collins appear to have been debunked by the State Services Commission.
The new email shows Slater claiming to a Herald journalist in 2011 that Ms Collins was trying to widen an inquiry into the former SFO director Adam Feeley.
Mr Feeley was facing questions over using a bottle of champagne belonging to an investigation target to toast his prosecution.
The email reads: "Spoke to Crusher [Ms Collins] yesterday, she has asked the SSC [State Services Commission] to widen the scope of their inquiries to look at staff turnover and culture etc," Slater wrote.