LONDON , England ( CNN ) -- Personal details and photographs of the incoming head of Britain 's international spy agency have been posted on Facebook , British Foreign Secretary David Miliband acknowledged Sunday . The UK 's Foreiogn Office says foreign service staff should exercise caution on social-networking Web sites . But he insisted that no compromising information had been revealed . `` You know he wears Speedo , swim , swimming , swimsuit ... I mean what is that ? I mean , that 's not a state secret , '' Miliband said on a BBC Sunday morning talk show . The man in question , John Sawers , is currently the British ambassador to the United Nations . His wife posted details about their family , vacations and residence on the social-networking site , British media reported Sunday . Her Web site has since been taken down , reports said . Have you ever posted something you later regretted on a social-networking Web site ? Sawers `` was appointed 10 days ago to be the head of MI6 , '' said Miliband , using the common term for the Secret Intelligence Service . `` He is an outstanding professional who will do a really good job in an outstanding organization that does a huge amount for this country , '' Miliband added . `` The fact that there is a picture , the head of MI6 goes swimming . I mean , wow ! That really is exciting . It is not a state secret . '' But intelligence analyst Glenmore Trenear-Harvey said the leak was at least an embarrassment and possibly much worse . `` Have you ever seen the foreign secretary more embarrassed ? '' he asked rhetorically . `` The Foreign Office should have made the announcement that no personal details should have been left on any computer or directory , '' Trenear-Harvey told CNN . The leak compromises Sawers ' personal security , said Trenear-Harvey , the editor-in-chief of `` The World Intelligence Review . '' `` You could have someone come online and insinuate themselves with Lady Sawers ' daughter , '' who reportedly appeared on the Facebook Web site . If she shares a computer with her father at home , `` the house could pick up a virus , and once that happens we have access to the next chief of the Secret Intelligence Service , '' the analyst said . An additional reason for red faces is that Sawers will be in charge of a new British cybersecurity organization when he becomes head of MI6 , Trenear-Harvey pointed out . The new organization , based at GCHQ , another British intelligence agency , will be `` charged with making sure that all the intelligence services are not vulnerable to hacking , identity theft , or phishing , '' Trenear-Harvey said . This is not the first time a top British intelligence official 's personal details have been leaked . When Richard Dearlove became the head of MI6 in 1999 , `` his address in Putney was announced , '' forcing the government to put Special Branch police officers there to protect him , Trenear-Harvey said . And when Stella Rimington became the first publicly named head of MI5 , the domestic security agency , in 1991 , her north London address was revealed . `` She and her daughter fled the house and were put into an MI5 safe house , '' Trenear-Harvey said . Foreign service officers `` are advised to exercise caution '' on social-networking Web sites , a Foreign Office representative said , declining to be named , in line with government policy . Sawers , 53 , is a career foreign policy expert . He was a foreign policy adviser to Tony Blair when Blair was prime minister , then became ambassador to Egypt and briefly represented Britain in Iraq . He was political director at the Foreign Office for four years before going to the United Nations in 2007 , according to his biography on the Web site of the British mission to the U.N . He is slated to replace John Scarlett in November as head of MI6 . As chief of SIS , he reports to the foreign secretary , according to the SIS Web site . `` Known as the Chief of SIS or ' C ' ( after the first Chief , Mansfield Smith Cumming , who signed himself ' C ' ) , the Chief is the only serving member of the Service who is officially named in public , '' according to the agency . Facebook claims to have `` over 200 million active users . '' -- CNN 's Ashleigh Nghiem contributed to this report .
NEW : Analyst : Leak is an embarrassment at the least , possibly worse . Wife of new spy chief John Sawers posted family details on social networking site . Foreign Office : Foreign service officers advised to exercise caution on Web sites . UK foreign minister : It 's not a state secret that he wears Speedo swimsuits .