The short seller targeting Valeant used a full page of his new report to rip into Bill Ackman

Short seller Andrew Left slammed hedge fund manager Bill Ackman in his latest report on embattled drug company Valeant Pharmaceuticals.

Ackman and Left are on opposite sides of a debate over Valeant's transparency, with Left's Citron Research alleging accounting fraud at the Canadian company.

Ackman's Pershing Square Capital, Valeant's third largest shareholder, has lost close to $1.9 billion this year as Valeant's shares have tumbled.

Here's a sample of what Citron's latest report said:

"If Mr. Ackman feels so much moral indignation about a company selling health shakes to people and takes such umbrage at their sales channel that he launches a full on jihad against them, how can he stand by a company that charges $300,000 a year to cure Wilson's disease."

If a person does not get their Wilson disease medication Syprine, acquired by Valeant, they die a slow and painful death. After increasing the price of this a simple medication, which as been available for 50 years and costs just $100 in Europe, to $300,000 per year, the co-pay alone chokes out families with someone suffering from one of the worst diseases on earth."

Left had previously said that his short "is not personal" and has nothing to do with Ackman.

"I have nothing with Ackman," Left told CNBC on Monday. "Why would I have anything with Ackman? He's a respected man. He makes big bets. He's very right sometimes. He's very wrong sometimes."

Much of those losses have happened in the past two weeks after Citron published a report suggesting Valeant may be operating as an Enron-like fraud.

On Friday at 11:25 a.m. ET, while Ackman was hosting a four-hour conference call defending his position in Valeant, Citron Research tweeted that it would release a new report on Monday with more dirt on the company.

"$VRX has a better chance of going to 0 than $HLF ever will," Citron tweeted, adding that the story was "dirtier than anyone has reported!!"

The $HLF in the tweet referred to Herbalife, whose stock Ackman is short - for almost three years he has been betting that its stock will go to $0. Ackman believes that Herbalife, a multi-level marketing company that sell weight loss shakes, is a "pyramid scheme" that prey upon lower income people.

Citron's updated report on Monday had no new bombshell allegations, but it did include a full page dedicated to Ackman.

Left ended his Ackman attack with the following question:

"BTW, Mr. Ackman should answer this question: Did he actually buy two million more shares of Valeant when the price plunged, or did he have 2 million shares put to him in an option position gone upside down?"

What Left is suggesting is that Ackman may have been forced to buy the shares from the puts owner.

We've reached out to Ackman for comment and have not heard back at the time of publication.