Stuart Rose, chief executive of Marks & Spencer, is understood to have issued Data Protection Act notices that would force the recipients to disclose information they are holding on him.

The notices were thought to have been served last night on several people involved in the acrimonious battle for control of the retailer.

The move follows the revelation on Tuesday that an unauthorised party had accessed Mr Rose's mobile telephone records without his knowledge.

The records are sensitive because of the Financial Services Authority's (FSA's) inquiry into share dealings surrounding Philip Green's approach to the company.

Mr Rose and Mr Green were quizzed by the FSA on Tuesday about the timing of certain conversations and share trades.

Mr Michael Spencer, chief executive of Icap, the interdealer broker, is expected to meet the FSA this week to discuss his purchase of contracts for difference (CFD) in M&S stock worth £5.5 million, on May 11th, a day after a meeting with Mr Rose.

He said yesterday he was intrigued about how his dealings had become public, given that the CFD trade would not have shown up on share registers. "I would like to be enlightened about that."

Mr Green was forced by the Takeover Panel yesterday to clarify his intentions for the third time since declaring his interest in M&S.

His bid vehicle dismissed an article in the Times newspaper that said he had told his team he would abandon his proposal by the end of July unless Marks & Spencer opened discussions.