Security expert Will Geddes claims MI5 and Scotland Yard have a solid track record of working together, but tensions can sometimes arise when it comes to prosecuting and obtaining intelligence.
He said: “Whilst the cops always want the collars the spooks want the information and it is a challenge getting the right balance.
“Choudary was certainly clever and knew where the line was and that was part of the reason it took so long to get him, but it was certainly possible that MI5 wanted to continue to monitor him because he was the focal point of so much.
“Given how influential he was in terms of setting up the forums for those guys to get inspired, it made perfect sense for the intelligence agencies to say ‘we haven’t exhausted this yet’.
“In the end though he got caught because he believed his press too much and he got carried away with his own media profile.”