Washington, July 21 : Billionaire and long-time ally of former US President Donald Trump -- Thomas J. Barrack, has been arrested in Los Angeles for allegedly acting as an agent of a foreign government. The 74-year-old investment firm founder served as a key adviser to Trump's 2016 campaign, and was considered a top fundraiser. Barrack has been accused of illegally lobbying on behalf of the United Arab Emirates (UAE) during and after the campaign, the BBC reported on Wednesday. A spokesman for Barrack said he has planned to plead not guilty. He is the latest ex-Trump official to face federal charges. Barrack is charged with conspiracy, obstruction of justice and making multiple false statements to the FBI during a 2019 interview. Also charged are Matthew Grimes, 27 - who works for Barrack, and UAE citizen Rashid Sultan Rashid Al Malik Alshahhi, 43, according to the seven-page indictment. Acting Assistant Attorney General Mark Lesko said the conduct alleged in the indictment was "nothing short of a betrayal" of US officials including Trump himself. The three men are accused of seeking to advance the interests of the UAE government both by influencing Trump officials and through media appearances. In May 2016, Barrack is alleged to have inserted language praising the UAE into a Trump campaign speech. An advanced draft of the speech was allegedly sent to Alshahhi to pass on to UAE officials. The defendants are also alleged to have received "talking points" from senior UAE officials for use in media appearances, the BBC reported. "After one appearance in which Barrack repeatedly praised the UAE, Barrack emailed Alshahhi, 'I nailed it... for the home team,' referring to the UAE," the charging document states. The men also allegedly agreed to promote the candidacy of a UAE-favoured individual to serve as US ambassador to Abu Dhabi. In December 2016 - following the election - Barrack is also alleged to have advised Grimes and Alshahhi to create a "wish list" of US foreign policy items that the UAE wanted to see accomplished during the Trump administration. While Barrack and Grimes were both arrested in California on Tuesday morning, Alshahhi remains at large. With the announcement, Barrack becomes the latest Trump aide to face criminal charges, including former campaign chairman Paul Manafort and former Trump Organization lawyer Michael Cohen. /IANS