The National Audit Office (NAO) examined 90 severance payments made to corporation bosses after its initial study of 60 cases showed some staff were paid more than they were entitled to.
The NAO said that in 18 of the additional 90 cases, severance deals had been agreed "before the supporting business cases had been through the relevant scrutiny and approval process".
The NAO report states: "The results of our examination of 90 severance cases confirm the conclusion set out in our earlier report, namely that weak governance arrangements led to payments that exceeded contractual entitlements and provided poor value for money."
Meanwhile, the BBC has published a separate report by auditors KPMG examining severance payments from July 2006 to December 2009.
BBC chief Tony Hall said new measures would strengthen the controls he had put in place.