You need to look at the case of Tony Farrell.
Tony Farrell was a Senior Intelligence Analyst with West Yorkshire Police.
He was asked to write and present a risk assessment report of the terror threat to the UK.
After looking at the evidence for 9/11 and 7/7 he realised the official version of events did not hold true.
He concluded that the greater threat was not from Islamic terrorism, but from the UK government.
His risk assessment was going to state this but he was asked to change it but refused.
After 12 years as an Analyst he was sacked.
He has lost an appeal to be reinstated, but is seeking further legal redress.