NEW YORK, Dec 14 (Reuters) - A son of the former Panamanian President Ricardo Martinelli pleaded guilty on Tuesday to a U.S. money laundering charge linked to Brazilian construction firm Odebrecht, becoming the second of his children to admit wrongdoing. Ricardo Martinelli, 42, who shares the same name as his father, entered his plea in federal court in Brooklyn, New York, after being extradited to the United States from Guatemala on Friday, prosecutors said. He pleaded guilty to one count of conspiracy to commit money laundering. His plea comes after his younger brother, 39-year-old Luis Enrique Martinelli, pleaded guilty the same charge earlier this month. The U.S. Department of Justice alleges that the brothers were intermediaries for the payment of some $28 million in bribes from Odebrecht to a Panamanian official while their father was president between 2009 and 2014. The elder Ricardo Martinelli has not been convicted of any crimes, but he remains under investigation in Panama due to a separate ongoing probe concerning Odebrecht. The Brazilian firm pleaded guilty to bribery and money laundering charges in 2016 related to the payment of more than $700 million in bribes to officials across Latin America to win contracts.