Philip Robinson, head of the crime division at the Financial Services Authority (FSA), said the increased supervision was needed to counter the increasingly inventive ways in which militants were laundering dirty money.
I dont think it is possible through the normal anti-money laundering regime to spot terrorism finance, Mr Robinson said in an interview with Reuters.
It is very possible for this to be going on and for it to be very difficult to detect. Since the Sept 11, 2001 attacks, financial authorities have sought to identify and seize so-called dirty money that could be used to fund atrocities.
But experts are increasingly skeptical, saying relatively small amounts of money sometimes carried across borders as cash could suffice to mount attacks. Mr Robinson and other law enforcement authorities say that criminals and terrorists are becoming increasingly inventive.
He said the cash from crime, that does not pile up in basements or leave Britain in shipping containers, was being laundered in part through the financial sector. Its going out through the financial services industry. I know it is. I just dont know where, he said.