London Mayor candidate Zac Goldsmith has made some £10 million from trusts, asset sales and salary over the past five years - and paid more than £4.5 million in tax.
The Tory MP revealed the details as he published a letter from his accountants, and challenged rivals to do the same.
Since 2010, Mr Goldsmith's income has totalled just over £6 million, the overwhelming majority apparently from a trust linked to the fortune of his late father, Sir James Goldsmith.
He paid nearly £2.8 million of tax on the sum - a rate of 46%.
A further £4.3 million came from assets sales, on which he paid around £1.7 million of capital gains, according to the letter from PricewaterhouseCoopers.
Mr Goldsmith, reputed to be the wealthiest member of the Commons, said he was previously "non dom" for tax purposes due to his father's "international status".
But he added: "It was not a choice, and I relinquished it seven years ago. I was born, grew up and have always lived in London - except for two years travelling abroad in my early 20s.
"Because of this I derived very little, if any, benefit from this status as my income came to the UK and was therefore taxed here.
"It is no secret I was dealt a good hand in life, but I have been determined to play it well.
"I have stood up for my local community in Parliament for six years, delivering on my promises to them - which is why they returned me with one of the biggest increased majorities at the last election.
"I am proud of my record and I will stand up and deliver for all of greater London, just like I have for Richmond, should I be elected mayor in May."
Conservative MP Paul Scully urged Labour's mayoral candidate Sadiq Khan to follow Mr Goldsmith's example.
Mr Scully said: "Zac has delivered on his commitment. With every day that Khan dodges the question, he's hiding from transparency."