2 ATTEMPTS CITED
sources close to Watergate case rept on May 7 that Pres Nixon, invoking natl security, sought on at least 2 occasions within last 2 wks to prevent release to ct of details of burglary at office of former psychiatrist of D Ellsberg, Dr L J Fielding; Nixon, in 1 case, was said to have reversed himself after receiving contrary recommendation from Asst Atty Gen H E Petersen in charge of Watergate investigation; reptd attempt to postpone release of information came after Justice Dept recd memo on Apr 16 or 17 from E J Silbert, chief prosecutor in Watergate case; in 2d case, information was reptdly provided to Fed Ct investigating Pentagon papers case at insistence of Defense Sec E L Richardson; 2d attempted delay came after former Pres aide E Krogh Jr was told by J D Ehrlichman that Nixon 'doesn't want any more of this to surface for security reasons'; White House on May 3 issued guidelines to Krogh telling him that he was free to testify regarding steps taken about Ellsberg but advised him that he was not authorized to discuss details of specific leaks or any information about specific security concerns; Krogh, in affidavit rleased on May 7, told of receiving rept from FBI indicating that Pentagon papers had been in possession of Soviet Embassy in Washington prior to their pub in June '71, in NY Times; affidavit also refers to Times article on US position in strategic arms limitation talks; White House sources have indicated this kind of information was considered too vital to natl security to be transmitted to Fed Dist Judge W M Byrne Jr, presiding over Pentagon papers case; Byrne's decision to release Silbert memo reptdly angered many officials in Justice Dept and White House