Iran Says There's A Missing Persons Case Into Former FBI Agent

The transcript discusses the disappearance of former FBI agent Robert Levinson, who went missing in Iran in 2007. Iran has acknowledged an ongoing case involving Levinson in its courts, typically handling espionage and other serious charges. However, Iran's Foreign Ministry states there is no judicial case against him. The US has offered a $20 million reward for information, claiming Levinson was taken hostage by Iran, though Iranian officials deny knowledge of his whereabouts. The date of Iran's filing to the UN remains unclear.

What did the US claim about Levinson's situation?

What is unclear regarding the filing to the UN?