The party also alleged that the encroachers had patronage of a minister from the Uttar Pradesh government.
Senior AAP leader and party in-charge of Uttar Pradesh Sanjay Singh today met Union Home Minister Rajnath Singh and put forward the party's demand.
"We met the family of the deceased policemen and they have demanded a CBI probe into the matter. We met Union Home Minister Rajnath Singh and have made this demand," Singh said.
On Saturday, Singh visited Mathura along with party MLAs and demanded a Supreme Court-monitored probe into the matter.
Delhi Chief Minister Arvind Kejriwal had also spoken to the family of slain policemen and assured them all possible help.