GST on Unrealised export - Goods and Services Tax - GST

A client of mine effected export by despacthing goods by ship. To their misfortune the ship was hijacked and goods never reached the destination. On technical grounds my client could not get any compensation from insurance company. My query is whether the client should pay applicable out put tax on the export value or it is enough if ITC is reversed on the cost of the inputs of the goods stolen as provided under sect 17(5)(h) of the CGST Act . If the opinion of the experts is, applicable output tax is payable, then the party is liable to pay the tax with interest to be calculated after expiry of 9 months from despatcth If the opinion of the experts is that, only ITC on inputs is to be reversed, then it should be done based on the date of hijacking of the ship.