corroborate

They said witnesses had been coached by investigators, in order to corroborate the theory of guilt.

"These incidents include only those that HRL corroborated through either remote sensing, open source documentation, or a combination of both methods and are likely an undercount," its report said.

They say Mas'ud's version of events is implausible and untrue, and argue that the contents of the statement can be corroborated by reliable independent evidence gathered over many years.

Other headhunters who scout for Indian talent from US universities corroborate this change in sentiment.

Over the next seven months, covert recording allowed the BBC to gather clear evidence corroborating what whistleblowers had described.