Two arrested over horsemeat scandal 29 August 2013 Last updated at 17:43 Two men have been arrested on suspicion of conspiracy to defraud by detectives investigating the horsemeat scandal, City of London Police has said. The force launched an inquiry in May but delayed releasing details of the men's arrests for "operational reasons." Two other men have been interviewed under caution. Horsemeat was discovered in processed beef products sold by a number of UK supermarket chains in March. Deliberate and coordinated Det Ch Supt Oliver Shaw said: "This is an extremely complex investigation covering a number of jurisdictions and a variety of businesses. We are working closely with police forces, other law enforcement agencies and regulators to determine whether horse meat being used in a range of meat products was deliberate and coordinated criminal activity. City of London Police worked with the Food Standards Agency (FSA) as part of its inquiry. It reviewed evidence from law enforcement agencies in Europe and the UK, as well as from the FSA. Last month MPs said they were "dismayed" at the slow pace of the national investigation into the scandal, with no prosecutions six months after the problem was first identified. An Environment, Food and Rural Affairs Committee report said mislabelling horsemeat as beef in the UK and Ireland had been "highly organised."