"Beyond the mob's inhuman behaviour, it is alarming to note that the police have sent the meat from the victim's refrigerator to a forensic lab to be tested, out of apparent respect for the mob's feelings," a statement posted on the IAMC website said.
"This effectively turns the victim into the accused, despite the fact that even if the family were in possession of beef, they were not in violation of the Uttar Pradesh Cow Protection Act," the statement added.
The IAMC also accused the authorities for their inaction, calling on the media to "expose the larger design behind the incident".
A week ago, Mohammad Akhlaq, a resident of Bisara in Greater Noida, was dragged out of his house after a mob alleged he had killed a cow in his house.
The IAMC said the incident was made to appear like a spontaneous act of violence by an unruly crowd but there are strong indications that this was a planned act.
The lynching was intended to terrorise the Muslim population of the area and suppress dissent across India over the beef ban implemented in some states, it added.
The IAMC is an advocacy group of Indian Muslims in the US "dedicated to safeguarding India's pluralist and tolerant ethos".