Anti-corruption officials in Mexico are investigating the attorney-general's office in the central state of Morelos after it was accused of covering up the murder of a young woman, Ariadna López.
The body of López, 27, was found by a highway in Morelos last week.
Morelos's attorney-general's office said she had choked while being drunk.
But a second post-mortem done in Mexico City concluded she had died of multiple force trauma.
Mexico City's mayor said the Morelos attorney-general's office "wanted to hide the femicide, presumably because of links with the presumed killer".
In a statement, the attorney-general's office in Morelos "categorically" denied the accusations, saying that they lacked "any basis".
The disappearance of Ariadna López and the subsequent discovery of her body have again shone a spotlight on murders of women in Mexico and their handling by state officials.
Mexico has seen a surge in femicides - murders in which women or girls are killed because of their gender - in recent years. In 2021, a record 1,004 femicides were registered across Mexico.
