MI5 has revealed the "secret to successful spying" with the first post on its new official Instagram account.

MI5 posted the message with a behind the scenes picture of its headquarters in London.

"Consider all angles. It'll give you a better view," the post said.

The account - @mi5official - will reveal never-before-seen archive material, show online Q&As with serving intelligence officers, and promote career opportunities.

Historical exhibits from MI5's museum, located in the basement of the agency's London headquarters, will also be shared for the first time.

The post added that "behind the pods lie some of the UK's best-kept secrets", teasing exclusive images of life at MI5 in future posts.

In October new director general Ken McCallum said that he wanted MI5 to "open up and reach out in new ways", particularly to communicate with younger audiences.

"Much of what we do needs to remain invisible, but what we are doesn't have to be," he said.

"In fact, opening up is key to our future success."

Writing in The Daily Telegraph on Thursday, he said: "In an increasingly open and connected world, MI5, and any forward-thinking intelligence organisation, faces a dilemma.

"On the one hand, our ability to serve the public and keep the country safe depends critically on operating covertly.

"But the other half of the dilemma is that MI5's ability to keep the country safe and resilient also depends on our reaching out to others who can help us, and whom we in turn can help.

"We owe it to the public to be constantly striving to learn and improve; and in our fast-moving world, with technology advancing at incredible speed, it would be dangerous vanity to imagine MI5 can build all the capabilities it needs inside its own bubble."