There has been no Sinn Féin response to claims yesterday that Mr Gerry Adams engaged in covert and indirect talks with Mrs Thatcher's governments and that he was in a position of responsibility within the IRA when Mrs Jean McConville disappeared and was murdered.
The claims, contained in a book published today by the former Irish Times Northern Ireland correspondent, Ed Moloney, were summarised in some weekend newspapers.
The book is set to allege that Mr Adams was connected to talks between the republican movement and the Thatcher government in 1986, just two years after the IRA came close to killing her during the Tory conference in Brighton in 1984.
The book also claims that the Sinn Féin president was in charge of an IRA unit responsible for the killing of Mrs Jean McConville, a mother of 10.
The book also links Mr Adams to the IRA policy of murdering and disposing secretly of the bodies of alleged informers. It alleges that Mr Adams set up "two secret cells" to carry out "special operations" on behalf of the Belfast brigade.
It also states that the killing of Mrs McConville could not have happened without the knowledge of Mr Adams.
Mr Moloney's publishers have claimed that the book, A Secret History of the IRA, reveals that the origins of the current peace process lay in exchanges between republicans and the British government up to four years earlier than was first thought.
Despite Mrs Thatcher's public claims to the contrary, it is further claimed that the contacts with republicans were authorised from No 10 Downing Street.