THE Home Office was locked down today as core participants to the Spycops inquiry accused the department of a “state cover-up.”Victims who were duped into relationships with undercover police officers were in a standoff with security for about an hour.A 55-year-old man was “manhandled” by outsourced guards as the group tried to hand-deliver thousands of letters responding to a “rigged” Home Office consultation over the future of the public inquiry.