An anonymous 20-year-old sex worker who was one of three witnesses known to have survived a mass killing by the Mexican army that took place on June 30 has revealed that she was severely beaten, tortured and threatened by state investigators.

According to the AP article, the Mexican army had claimed to have come under fire and engaged in a shootout, resulting in the deaths of 22 drug game members, but left just one soldier wounded, in rural San Pedro Limon. When the woman refused to sign a false statement that asserted that the 22 suspected drug gang members had expired in a shootout with the Mexican army, the state investigators involved kicked her in the ribs, placed a bag over her head, plunged her face into a toilet bowl and beat her so profoundly that six months later she still has trouble seeing and hearing.

Seven soldiers and a lieutenant have been detained regarding the June 30 incident that, coupled with the killing in Mexico of 43 college students in Guerrero state, has sparked worldwide protests.

According to the witness -- who has spent five months falsely imprisoned on weapons possession charges -- the cover-up she was privy to implicates many more than the soldiers now facing trial in the case, and amounts to a list which includes state and federal prosecutors who strove to make the massacre appear as if it were the result of a gun-battle and not, as she maintains, an act of extra-judicial killings after a surrender.

When she told the state investigators that she was not going to sign anything she was berated, then battered, and finally, without an attorney present, she signed their statement.

As quoted in the AP article, the witness said: "As they were hitting me ... they told me they could make even the mute talk."