MI5's first female director general left more than £2million to her husband and daughters in her will.
Dame Stella Rimington, who headed the security service from 1992 to 1996, was widely credited as being the model for Dame Judi Dench's M in the James Bond films.
The former secret service chief, born Stella Whitehouse in London in 1935, died last August aged 90.
Newly released documents showed her estate was worth £2,081,105 when she died, with a net value of £2,064,821 after deductions.
Dame Stella left the bulk of the sum to husband John, daughters Harriet and Sophia in a trust.
She also left the proceeds of her literary estate to her grandchildren.
The spy chief retired from the service in 1996 and went on to publish her autobiography, Open Secret, in 2001. A number of spy novels followed.
She later said spy writers had created 'a totally glamorous world around the profession of spying' that 'bears very little relation to reality'.
Dame Stella Rimington, who headed the security service from 1992 to 1996, was widely credited as being the model for Dame Judi Dench's M in the James Bond films
Dame Stella, who died last August, pictured with former Home Secretary Michael Howard on July 16, 1993
Dame Stella revealed her novels had to be submitted to the security service for clearance, and that she had occasionally been asked to change names and places by MI5.
Dubbed the 'housewife superspy', she joined MI5 full time in 1969, and served as deputy director general in 1991 before being promoted to director general a year later.
Born in 1935 in South Norwood, south London, Dame Stella got her first role at MI5 as a part-time clerk typist in India, where she had accompanied her husband on a diplomatic posting four years earlier.
It was during the summer of 1967 when she was approached by a British official who asked if she would interested in 'helping out' in his office?
The author of the request was 'a baronet and a bachelor' best-known among staff at the British high commission for his 'excellent Sunday curry lunches' and for 'driving round Delhi in a snazzy old Jaguar'.
He was also the senior liaison officer for MI5 in the Indian capital, and her acceptance of his offer of employment marked her entry into the shadowy world of intelligence.
The Cold War and threats posed by the Soviet Union dominated much of her early career.
Speaking in 1999, Dame Stella said she had thoroughly approved of the decision to make her name public when she became director general, but added that she hadn't predicted how much interest there was going to be.
During her time as director general and following the end of the Cold War, threats from Russia continued to take up her time.
And she revealed the KGB once tried to recruit her at a dinner party in the 1960s.
Former MI5 boss Stella Rimington, who was conferred with the honour Dame Commander of the Order of the Bath in 1996
In her retirement, she took on several non-executive directorships, including Marks & Spencer, using her surveillance skills to eavesdrop on customers to find out what they were saying about the company's products.
When she died MI5 said she had a varied career in the service 'including roles in counter-subversion, counter-espionage and counter-terrorism'.
'MI5 underwent far-reaching transformation under Dame Stella's leadership,' a statement from the agency said.
'She oversaw MI5 taking lead responsibility for countering Irish republican terrorism in Great Britain, the move of MI5's headquarters to Thames House, and instituted a policy of greater public openness to demystify the work of MI5 including beginning a programme of releasing MI5 files to The National Archives.'