BRITAIN's Co-operative Wholesale Society (CWS) yesterday turned up the heat on predator Mr Andrew Regan by referring concerns about a previous deal between the two parties to Britain's Serious Fraud Office. "We have now formally drawn this situation to the attention of the SFO," a CWS spokesman said, adding that City law firm, Linklaters & Paines, had visited the SFO to voice its concerns. But an SFO spokeswoman said that the office was not investigating the affair sparked by the £1 billion-plus takeover bid by an offshoot of Regan's Lanica Trust.