BBC bosses investigating Huw Edwards took more than four weeks to respond to a new serious complaint that could aid their probe.
They only replied to the whistleblower, a recent ex-Beeb employee, the day after The Sun contacted them about it.
The complainant first contacted the BBC on July 13 – after news presenter Edwards, 61, was named as the suspended star whose behaviour was being investigated.
An email asked them to contact the BBC’s Corporate Investigations team, which they did two days later.
After not receiving a reply, they contacted the BBC again on July 31.