Ross Knowles, a 42-year-old boss at Kent County Council, is alleged to have siphoned off funds meant for big energy companies - which he used to buy a Jaguar car and trips abroad.
The respected 'golden boy' of his sector cashed in invoices for as much as £400,000-a-time into his own personal account, a court was told.
A jury heard that British Gas and NPower were two of the companies he defrauded, before being caught out.
Knowles worked with the Local Authority South East Region (Laser) buying energy for Kent County Council in 2007, Maidstone Crown Court heard.
Over a 14-month period, Knowles - who earned a salary of £66,000 a year - extracted more than £2million and kept it for himself, the court was told.
Allison Clare, prosecuting, told the jury that the Cambridge graduate was regarded as 'a bit of a star' and a 'golden boy'.
She said: 'He was a huge asset to Laser, everybody thought. That may be why he was able to perpetrate the fraud.
'The essence of the fraud is really very simple.'
Knowles would ask British Gas and NPower to add an extra charge at their end of their dealings as a 'comfort blanket', Miss Clare told the court.
This was meant to be reclaimed by Kent County Council and Laser at the end of the year.