Kraft Heinz Co. (KHC - Get Report)  shares tanked to an all-time low Thursday after the packaged food company's delayed second quarter earnings report revealed a further $1 billion in impairments owing to its investigation into accounting practices that led to the restatement of its financial results for 2016 and 2017.

Kraft said adjusted earnings for the three months ending in June came in at 78 cents per share, down 21% from the same period last year but firmly ahead of the Street consensus forecast of 61 cents per share. Group revenues, Kraft Heinz said, fell 16.3% to $5.595 billion, just shy of analysts' estimates of a $6.07 billion tally. Organic net sales over the first half of the year fell 1.5%, Kraft said, while first half profits more than halved, to $854 million, from the year-ago period. 

Kraft said its expects to record a non-cash impairment loss off $620 million in its first quarter results, as well as non-cash impairment of $124 million in the second quarter, noting" we continue to evaluate the amount of the impairments and execute and test certain internal controls" but could "... "make no assurances these estimates will not change".

"We have significant work ahead of us to set our strategic priorities and change the trajectory of our business," CEO Miguel Patricio told investors on a conference call Thursday.

Kraft Heinz shares were marked 13.57% lower immediately following the earnings release to change hands at $26.68, and all-time low and a move that extends the stock's year-to-date decline to around 38%.

Kraft said earlier this spring that its probe found that "several" of its employees in the procurement area of the group had engaged in misconduct linked to the recognition of costs and rebates, but added that senior management wasn't involved.

The adjustments clipped around 10 cents per share from Kraft Heinz's earnings over a period of just under three years, the company said, and will mean its fiscal fourth quarter report, for the three months ending in March, will be delayed.

Warren Buffett, whose Berkshire Hathaway (BRK.A - Get Report) investment group owns around 26.7% of Kraft Heinz, said he took a $3 billion goodwill writedown on the holding earlier this year, and wasn't able to book anything from the stake in Berkshire's first quarter earnings report owing to the delay in Kraft filing its 10-k with the SEC.

"It's pretty unusual. It means we put in zero for earnings even though we received $130 million in dividends but we don't count that in earnings because it's an equity type of investment, " Buffett told reporters during Berkshire's annual general meeting in Omaha, Nebraska.