A former head of M15, the domestic UK intelligence agency, injected a frisson of Cold War and counter-terrorism issues into a private banking conference and damned the actions of US spy agency leaker Edward Snowden.

It isn’t every day that a private bank conference hears a speech from a former boss of a renowned spy agency. But that is what happened in the sleek surroundings of Draper’s Hall in the City of London last week.

Dame Stella Rimington, former director general of M15 (holding the post from 1992-1996) and since then a nifty writer of fiction, addressed a conference organised by Butterfield. And what became clear is that this woman has decidedly strong views on the continuing and complex security threats faced by the UK both domestically and abroad.

The presence of such a person at a conference for wealth managers was the reason, this correspondent surmised, there was a full house. The question and answer session at the end of Rimington’s address produced plenty of sharp questions. WealthBriefing asked Rimington how she viewed the recent mass of cyber attacks on institutions such as JP Morgan, highlighting the threat to wealth management. (That US bank recently reported that data on 76 million people and 7 million firms had been affected by an attack. It has been rumoured but not fully substantiated, that the hackers have had foreign official support. Russia has rubbished any claims it supported the attack.)

Rimington said that security services take such cybercrime very seriously and are actively working with firms – she obviously did not say whom – to advise on becoming more robust in the face of such attacks.

In a talk that ranged from her early experience as a M15 employee in the Cold War through to the period when the UK faced attacks from the IRA in Northern Ireland, she was clear about how far the business of counter-terrorism and espionage has changed. What hasn’t changed, she said, was the continued need for credible, human intelligence. Technology is great – but it is not a complete substitute.

Finally, she commented on Edward Snowden, the US computer professional who leaked classified information from the National Security Agency. He has been called the biggest leaker from American spying ever and after fleeing the US, he now is resident in Russia (at least as far this publication can tell at the time of writing).

“The job of intelligence services has been made a lot more difficult because of the activities of Edward Snowden. Anybody who thinks Edward Snowden has struck a blow for liberty, freedom and security is greatly mistaken,” she said, arguing that strong security in today’s world was vital to freedom, not its enemy.

“We need our intelligence services now more than ever,” Rimington added.