New documents have revealed that a Johnson & Johnson vice president—the manufacturer of the patch—resigned in over the company’s repeated efforts to downplay the risk of Ortho Evra side effects. A letter by the executive—whose name was redacted by the court—was recently unsealed as part of a group of 400 Ortho Evra lawsuits that have been filed in New Jersey.

According to the executive’s letter to J&J chief executive William Weldon, he decided to resign as a result of the company’s efforts not to fully publicize evidence that the Ortho Evra birth control patch was potentially more dangerous than birth control pills. The executive said in the letter that these efforts had prevented him from acting on his responsibilities to oversee the risks and safety of J&J’s birth control devices. He added that he wrote the letter at the suggestion of co-workers who were also frustrated at the company’s efforts to downplay the risk of Ortho Evra side effects.

The vice president accused Weldon and J&J of publicizing early studies which saw an equal risk of side effects with the patch and Ortho Evra, even though it was aware of at least 20 deaths among Ortho Evra users after the birth control patch was released. The executive says that the company was also aware that the high levels of estrogen exposure caused by Ortho Evra could increase the risk of blood clots or other problems.

Studies have shown that Ortho Evra users receive about 60% more estrogen in their bloodstream than with birth control pills. Because estrogen can increase the risk of blood clots, this can put women in danger of suffering serious Ortho Evra side effects. A study by the Associated Press in 2005 found that women who use the Ortho Evra birth control patch are three times more likely to suffer blood clots than women who used birth control pills.

J&J has announced that it is currently facing at least 2,400 Ortho Evra lawsuit brought by former users of the birth control patch. These lawsuits allege that J&J was aware of the risk of side effects of Ortho Evra, but failed to make customers aware of the potential health risks they faced from using the patch.