Sajid Javid has admitted he previously held non-domicile tax status and kept money in an offshore trust.
Amid an ongoing row over Rishi Sunak's wife's non-dom status, the Health Secretary came clean about his own use of the scheme before entering Parliament in 2010.
Mr Javid also admitted to benefitting from an offshore trust when he worked for Deutsche Bank but said he voluntarily "collapsed the trust" when he became a minister in 2012.
Labour blasted him for "hypocrisy" over the revelations, which came after the Tories hiked national insurance contributions for millions of Brits last week.
Non-dom status is a legal scheme that allows people domiciled abroad to avoid paying UK tax on their overseas income.
The arrangement has come under scrutiny after it emerged that Mr Sunak's wife Akshata Murty held non-dom status, which could have spared her paying millions of pounds in UK tax.
Ms Murty bowed to intense political pressure on Friday and said she will now pay UK tax on her overseas income, which includes an estimated £11.6 million a year in dividends from her billionaire father's IT firm Infosys.
In a statement first reported by the Sunday Times, Mr Javid said: "I have been domiciled in the UK for tax purposes throughout my entire public life.
"Given heightened public interest in these issues, I want to be open about my past tax statuses."
After a posting in New York between 1992 and 1996, where he paid US taxes, Mr Javid returned to the UK where he was a tax resident.
He said: “For some of those years I was non-domiciled for tax purposes, but I paid all UK taxes due on my income and have always done so."
It is unclear where he was domiciled during this period but it is understood not to have been Pakistan, where his father was born.
Mr Javid went on: “In 2006 I moved to Singapore with my family and was therefore no longer a UK tax resident.
"In 2009, upon my return to the UK, I became tax-resident in the UK again and also proactively chose to give up my non-domiciled status by making the UK my ‘domicile of choice’."
He became an MP in 2010 and went on to hold a number of Cabinet jobs, including Chancellor from 2019 to 2020.
Mr Javid also admitted to having some financial investments based in an offshore trust before he returned to the UK and entered Parliament.
He said: "While this was an entirely legitimate arrangement, on becoming a minister in 2012 I decided to voluntarily collapse that trust, repatriate all assets to the UK and pay 50 per cent income tax on those assets.
“This approach deliberately incurred the heaviest possible tax burden, and offset any accrued benefits from the previous trust arrangement, but I believed it was the right thing to do.”
Shadow Health Secretary Wes Streeting said: "Last week Sajid Javid was lecturing struggling taxpayers about their duty to pay higher taxes, but this is the guy who spent six years as a non-dom and had an offshore trust to avoid paying his fair share of tax in Britain.
"Even now, he refuses to say if he was using a tax haven. The hypocrisy stinks.
"The luxury of being able to choose how much tax you pay, where you pay it, and when you pay it, is not one that is enjoyed by most people in this country."
