State media said the shock move was taken to detain Ali Shareef al Emadi as part of the ongoing probe.
The investigation was focused on “crimes related to the public sector,” but there was no clarification whether or not al Emadi himself was facing any charges.
It was later announced that al Emadi had been “relieved” of his position as finance minister and would be replaced by the minister of trade, Ali bin Ahmed al-Kuwari.
Al-Emadi had been in his post as finance minister since 2103.
An economist, he also serves on the board of the Qatar National Bank, though it is thought the investigation relates only to his work as a minister.
He also sits on the board of Qatar’s vast $300bn sovereign wealth fund, the Qatar Investment Authority, which has various interests in the UK including Heathrow Airport and The Shard building in London.
An arrest of such a high-ranking official on suspicion of corruption is extremely rare in Qatar.
Prior to Thursday’s announcement, al Emadi had enjoyed a reputation for helping the gas rich monarchy to navigate economic shocks such as the fall in energy prices in 2014 and 2015. He also helped Qatar overcome a trade and political blockade by several neighbouring countries which only ended in January after almost four years.
As finance minister, al Emadi would also been involved in key decisions in the run-up to next year’s football World Cup, which will be hosted in Qatar.
It will be the first time the finals have been held in the Middle East, though this has proved hugely controversial amid claims of corruption and human rights abuses, denied by Qatar.
The tiny state, it has a population of some 2.8 million, has overseen massive national infrastructure projects costing hundreds of billions of dollars in readiness for the event.
In 2017, al Emadi revealed that Qatar was spending close to $500 million a week on major projects for the tournament, and it would spend an eye-watering $200 billion in total in preparation for the World Cup.
The country has been utterly transformed for the tournament, building or refurbishing eight stadiums, a new airport, port, metro system and even a new city to host the World Cup final.
“We are really giving ourselves a good chance of delivering things on time and we don’t want to get in a place that we start painting while people are coming to the country,” he said then.
Super rich Qatar has transformed its economy largely through gas exports.
It is the world’s largest producer of super-chilled liquefied natural gas and shares the world’s biggest natural gas field with Iran.
Join our new commenting forum
Join thought-provoking conversations, follow other Independent readers and see their replies