Truss’ spokesman said he supported Fulbrook, who will not travel with her to the UN general assembly in New York this week. However, the Prime Minister herself refused to say whether she had been informed of his cooperation with the FBI before his appointment, saying only that he had gone through the “due process”. No 10 said Fullbrook’s decision not to travel with the prime minister was because he was working on government business, including the energy package for business on Wednesday and the mini-budget on Friday. A Downing Street spokesman said the Prime Minister stood behind Fulbrook 100% and had her “full support”. The FBI probe is related to allegations that Julio Herrera Velutini, a Tory financier and donor, promised to help the former governor of Puerto Rico get re-elected if she fired an employee investigating a bank owned there. He has denied the charges against him. A spokesman for Fullbrook said: “As has been made clear on several occasions, Mr Fullbrook is bound by and complies with all laws and regulations in any jurisdiction in which he works and is confident that he has done so in this matter. “Indeed, Mark Fullbrook is a witness in this matter and has fully, fully and voluntarily cooperated with the US authorities in this matter, as he always would in any circumstance in which his assistance is requested by the authorities. “The work was undertaken only by Mr. Herrera and only to conduct an opinion survey for him and no one else. Archie Bland and Nimo Omer take you to the top stories and what they mean, free every weekday morning Privacy Notice: Newsletters may contain information about charities, online advertising and content sponsored by external parties. For more information, see our Privacy Policy. We use Google reCaptcha to protect our website and Google’s Privacy Policy and Terms of Service apply. “Mr. Fullbrook never did any work for the governor or her campaign, nor did he present any investigative findings. Since then there has been no engagement. “Mr Fullbrook understands that there are active legal proceedings against other individuals and entities. Therefore, it would not be appropriate to comment further.”