One of Hillary Clinton's closest aides is at the centre of the new FBI investigation into the Democrat candidate's emails after it emerged the evidence was discovered during an investigation into her husband. Anthony Weiner is being investigated over allegations that he sent sexually explicit text messages to a 15-year-old girl. New York prosecutor [Preet Bharara] issued a subpoena for Mr Weiner's mobile phone and other electronic records after the "sexting" came to light in September. It is believed this sparked the reopening of the closed [Clinton] investigation. Mr Weiner [is] the estranged husband of Huma Abedin, 40, Mrs Clinton's closest aide. Mrs Clinton thought that the issue of her email server - which has been a millstone round her neck since 2012 - was finally settled, with the FBI deciding in July not to charge her with any criminal offence. Mrs Clinton was supposed to have handed over all evidence relating to her use of a private email server - something she instigated in 2009, when she was appointed secretary of state. The Weiner investigation shows she did not. Critics claim there was a security risk if restricted government business was sent over personal email servers. They also say Clinton could skirt around freedom of information requests and have sole control of what information was handed over to interested parties - such as the congressional committee investigating 2012's attack on the US consulate in Benghazi.