Highly likely IVA is hold engine until cash due is paid. ELIO has no money and the equipment is not selling. IVA is not going to turn over the engine until paid.
This is not true. The folks at IAV have proven themselves to be much smarter than the random people making stuff up on the internet as IAV simply does not extend credit to a new start-up company. Instead they broke the project down into sections with amounts due up front to complete the work. We know this from the last Elio Motor town hall.