Patel v Mirza [2016] UKSC 42 is an English contract law case concerning the scope of the illegality principle relating to insider trading under section 52 of the Criminal Justice Act 1993.

Using advance insider information to profit from trading in securities is an offence under section 52 of the Criminal Justice Act 1993.

The scheme did not come to fruition as the expected insider information was mistaken, and Mr. Mirza did not return the funds to Mr. Patel as promised.

Mr. Mirza argued that no such obligation could be enforced because the whole contract was illegal, and any claim would be precluded by the principle of ex turpi causa non oritur actio.

Instead, the court should consider whether the public interest would be harmed by the enforcement of the illegal agreement, taking into account: