The emissions scandal is the big, polluted raincloud that just won’t let the sun shine on Volkswagen.

As if the German carmaker’s fortune couldn’t get much worse, it has been revealed that senior managers were warned about a possible probe into cheat device software installed on the cars as early as May 2014. According to German newspaper ‘Bild am Sonntag’ the warning came in the form of a letter written by one of the company’s high ranking employees. Though nothing can be proven, the existence of such a letter spells even worse news for the beleaguered company who might have been able to avoid the emissions scandal.

The paper reports that an employee wrote to Martin Winterkorn -who was CEO at the time – informing him that that they could not provide an explanation for the rise in nitrogen oxide emissions and that the automobile and environmental authorities would look for the cheat device software used to lower emission figures. Though this new allegation has a ripple effect comparable to that of a single drop in the ocean for Volkswagen who have been plagued by lawsuits and penalties since the emission scandal became public last year, it does lead to questioning about just how much senior figures at Volkswagen knew about the scandal, and just how much they could have done to prevent it becoming the global PR disaster it became.

When Volkswagen eventually admitted to the scandal back in 2015, it was suggested that there was only a small number of employees involved and there was little indication that the board members had any knowledge. Winterkorn himself explicitly denied any knowledge, and when he announced his resignation as CEO shortly after the scandal broke he said “I am doing this in the interests of the company even though I am not aware of any wrongdoing on my part.” It probably won’t come as much of a surprise to anyone to hear that reps for Volkswagen and Winterkorn were not available for comment when contacted by the German newspaper regarding this new development.

Did muddy waters just get muddier for Volkswagen, or have they become an easy, yet understandable, target?