Guy Hands, the private equity tycoon, was on Wednesday forced to defend his investment acumen in a £22m lawsuit over a film financing scheme that produced the tale of a boxing shrimp and other box-office clunkers.

Mr Hands and his wife, Julia, are two of 75 investors who are suing Baker Tilly, the accountancy firm, and Adrian Shipwright, a barrister, for negligence in signing off on the scheme, which allegedly promised huge tax breaks without any risk.