Jeff Bezos has clashed with US President Joe Biden's administration on Twitter over the cost of petrol for American consumers.
Mr Biden had tweeted this weekend that "this is a time of war and global peril" and that the companies running gas stations were acting out of greed.
"Bring down the price you are charging at the pump to reflect the cost you're paying for the product. And do it now," he wrote, as inflation in the US reached a 40-year high.
"Ouch," the billionaire wrote. "Inflation is far too important a problem for the White House to keep making statements like this. It's either straight ahead misdirection or a deep misunderstanding of basic market dynamics."
Mr Bezos has repeatedly used Twitter to criticise the White House's approach to rampant inflation in recent months, something which the US leader has mainly blamed on the Russian invasion of Ukraine.
Since stepping down as the chief executive of Amazon, Mr Bezos has been a frequent user of the platform. In May he accused the president of misleading the public about inflation.
His comments provoked an unusually personal criticism in which a White House spokesperson accused the billionaire of attempting to undermine unions and protect his own wealth.
White House spokesperson Andrew Bates said: "It doesn't require a huge leap to figure out why one of the wealthiest individuals on Earth opposes an economic agenda for the middle class that cuts some of the biggest costs families face... by asking the richest taxpayers and corporations to pay their fair share.
"It's also unsurprising that this tweet comes after the president met with labour organisers, including Amazon employees."
In a similarly personal response this weekend, White House press secretary Karine Jean-Pierre said: "Oil prices have dropped by about $15 (£12) over the past month, but prices at the pump have barely come down.
"That's not 'basic market dynamics'. It's a market that is failing the American consumer," she wrote.
"But I guess it's not surprising that you think oil and gas companies using market power to reap record profits at the expense of the American people is the way our economy is supposed to work."