What is the most likely theory behind the Daniel Morgan case?
From what I can presume the most likely theories are it was either Jonathan Rees who had him killed so he could simply take over the business and then had his buddies in the Met cover it up.
Or Sid Fillery was made aware of Daniel's supposed Investigations into Met corruption had him killed and Jonathan Rees was in on it as Daniel had become too difficult to work with.
Another theory (which I am aware is even more conspiratorial) is that Daniel was unravelling not just police corruption but had found out about the numerous perverse ways journalists were using to obtain information that would eventually come to light years later in the News of The World Scandal and the subsequent Leveson inquiry. That Jonathan Rees & Sid Fillery, the Vian Brothers and James Cook were acting on behalf of a much more powerful unknown figure possibly within the Met or within Fleet Street.