A potential $500m order for wind farm vessels by Triumph Subsea at UK shipbuilding group InfraStrata has collapsed amid a volley of accusations on both sides.

In a trading update on 30 June, the London-listed owner of Belfast shipyard Harland & Wolff (H&W) said it had "set aside for the time being" a letter of intent (LOI) for one firm and one optional 200-metre wind farm development (WDV) vessel agreed with the Croatian start-up in December 2020.