Qatar Finance Minister Ali Sharif Al-Emadi was arrested for questioning over allegations of embezzlement, abuse of power and crimes related to the public sector, a statement carried by state news agency QNA said on Thursday.
An investigation is underway, the statement added.
Emadi has been minister of finance since 2013 and sits on the board of its powerful $300 billion sovereign wealth fund, the Qatar Investment Authority.
He is also chairman of the board of directors of Qatar National Bank.
Emadi steered Qatar's economic policies during the 2014-2015 oil price crash that prompted the country to accelerate plans to diversify the economy.
He was named as 2020’s best minister in the region by The Banker, an international financial magazine that organises an annual celebration of finance ministers.
Qatar, which next year will host the FIFA World Cup, has invested heavily in infrastructure over the past few years ahead of the event, which means spending on major projects is set to decrease this year, the finance ministry has said.
Iran and Israel targeted each other with missiles and airstrikes early on Saturday after Israel launched its biggest-ever air offensive against its longtime foe in a bid to prevent it from developing a nuclear weapon.
Israeli fire and airstrikes killed at least 35 Palestinians across the Gaza Strip, most of them near an aid distribution site operated by the US-backed Gaza Humanitarian Foundation, local health authorities said.
The death toll from the Air India plane crash in Ahmedabad rose to 270 on Saturday, as grieving families expressed frustration over delays in the release of victims' bodies, many of which were badly charred in the tragedy.
US President Donald Trump urged Iran on Friday to make a deal on its nuclear programme before it faced more attacks from Israel that he said would be "even more brutal."
Israel launched widescale strikes against Iran on Friday, saying it targeted nuclear facilities, ballistic missile factories and military commanders and that this was start of a prolonged operation to prevent Tehran from building an atomic weapon.