Gordon Brown has earned more than £1.4m since he stepped down as prime minister, with much of his income coming from touring the international lecture circuit.
Among the payments received were £49,052.69 for speech to King Saud University in Saudi Arabia, £61,637.68 for a speech in Moscow and £74,936.79 for an address in Nigeria.
He received a £78,289.61 advance for his book Beyond The Crash, which detailed the events of the 2008 financial crisis.
And the former prime minister and chancellor gets paid £102,568.55 for his role as a "distinguished global leader in residence" at New York University.
However Brown notes that most of the money he earns is used by the Office of Gordon and Sarah Brown in order to pay staff, support charity work and their "ongoing involvement in public life" - rather than for personal gain. And the profits from his book were donated to charity.
The figures are revealed in the recently published House of Commons register of members' interests, which details donations to MPs.
Brown stepped down as prime minister in May 2010, but he continues to draw a salary of £65,738 as MP for Kirkcaldy and Cowdenbeath and as such has to provide details of his earnings.
Much of his time is spent focused on a charity campaign to educate an extra 69 children worldwide by 2015 and a spokesperson for the former prime minister said "not a single penny" from speeches nor books goes to him personally.
"As the Register of Members' Financial Interests makes clear for every event Mr Brown undertakes Mr Brown personally receives nothing at all because he donates all money either direct to charities or to support Sarah and Gordon's charitable and public service work," they said.
"A list of some of the many charitable projects Sarah and Gordon support including PiggyBankKids is contained on their website. Indeed Mr Brown's sole personal earnings are his salary as an MP because he has also renounced the prime ministerial pension he was entitled to receive immediately he retired as PM."
Brown's post-prime ministerial income is dwarfed by that of Tony Blair, who is estimated to have made £12m since he left Downing Street in 2007.
He has also kept a relatively low profile since leaving office, making on sporadic appearances in the Commons chamber and conducting very few media appearances.
However he is expected to play a role in the upcoming referendum on Scottish Independence. Yesterday David Cameron said he hoped his predecessor would speak out in favour of the union once the poll drew closer.