VANCOUVER/TORONTO -- Asanko Gold Inc (AKG.TO) on Wednesday disputed claims by U.S. hedge fund Muddy Waters that the Canadian company would run out of cash due to problems with its Ghana mining operations.

News that Muddy Waters was shorting the small Vancouver-based miner's shares had pushed them down 31 per cent in the United States and 13 per cent in Canada on Wednesday morning, before trading was halted.

Muddy Waters released a 43-page report that detailed why it was betting the stock would fall.

Asanko responded Wednesday afternoon by promising to release an expanded feasibility study on its mine plans on Monday, which it said would "provide a complete rebuttal" to claims from Muddy Waters, a San Francisco firm run by prominent short seller Carson Block.

"The Asanko Gold Mine is a robust business," Asanko Chief Executive Peter Breese said in a statement.

He reiterated the company's previous forecast that it would produce 230,000 to 240,000 ounces of gold this year, which it expects will generate between US$64 million and US$77 million in cash. That forecast assumes a US$1,200 an ounce gold price. Spot gold was quoted at US$1,269.11 an ounce late Wednesday.

The Muddy Waters report, which the investment fund published on its website, said production at its Nkran mine and other deposits would not meet the company's expectations because the estimates were based on flawed geology.

The report predicted that production shortfalls would cause Asanko to run out of cash next year as it struggles to repay US$165 million in debt.

The report outlined concerns that other commentators already had raised, most of which had either been acknowledged by management or would likely be addressed on Monday, BMO analyst Andrew Breichmans said in a note to clients.

Maria Smirnova, a senior portfolio manager at Sprott Asset Management, an Asankoshareholder, said it was "a shame" that the miner had been targeted by Muddy Waters.

"I view the Asanko management team as having the utmost integrity and always doing what's best for shareholders," said Smirnova, whose firm is the miner's eighth-largest shareholder, according to Thomson Reuters data.

Van Eck Associates, Asanko's biggest shareholder with a 20.4-per-cent stake based on latest publicly available data, did not respond to a request for comment.

Toronto hedge fund K2 & Associates Investment Management Inc in June 2016 took a short position in Asanko, saying its gold resources were overinflated, notably at its Nkran deposit, which Asanko acquired in 2014 from Resolute Mining Ltd.

K2 could not be reached for comment on Wednesday.