Lord Atkin:… The story starts with the action of debt which was not necessarily based upon the existence of a contract, for it covered claims to recover sums due to customary dues, penalties for breaches of bylaws, and the like. The action of debt had its drawbacks, the chief being that the defendant could wage his law. There followed the application of the action on the case of assumpsit to debt. The defendant being indebted then promised.’ At first, there must be an express promise; then the courts implied a promise from an executory contract: Slade’s case. Slade’s case was not a claim in indebitatus assumpsit, but the principle was applied, and it became unnecessary to prove an express promise in those cases. Then the action was allowed in respect of cases where there was no contract, executory or otherwise, as in the cases where debt would have lain for customary fees and the like; and by a final and somewhat forced application to cases where the defendant had received money of the plaintiff to which he was not entitled. These included cases where the plaintiff had intentionally paid money to the defendant, for example, claims for money paid on a consideration that wholly failed and money paid under a mistake: cases where the plaintiff had been deceived into paying money, cases where money had been extorted from the plaintiff by threats or duress of goods. They also included cases where money had not been paid by the plaintiff at all, but had been received from third persons, as where the defendant had received fees under colour of holding an office which in fact was held by the plaintiff: and finally cases like the present where the defendant had been wrongfully in possession of the plaintiffs goods, had sold them and was in possession of the proceeds. Now
to find a basis for the actions in any actual contract whether express or to be implied from the conduct of the parties was in many of the instances given obviously impossible. The cheat or the blackmailer does not promise to repay to the person he has wronged the money which he has unlawfully taken: nor does the thief promise to repay the owner of the goods stolen the money which he has gained from selling the goods. Nevertheless, if a man so wronged was to recover the money in the hands of the wrongdoer, and it was obviously just that he should be able to do so, it was necessary to create a fictitious contract: for there was no action possible other than debt or assumpsit on the one side and action for damages for tort on the other. The action of indebitatus assumpsit for money had and received to the use of the plaintiff in the cases I have enumerated was therefore supported by the imputation by the court to the defendant of a promise to repay…
Rowland v Divall  2 KB 500 Court of Appeal
(See p 236.)
Lipkin Gorman v Karpnale Ltd  2 AC 548 House of Lords
A partner in a firm of solicitors embezzled cash from the firm’s bank account
and lost the money gambling at the defendants’ casino. When the solicitors brought an action in debt (money had and received) to recover the lost cash, the gambling club claimed that they were bona fide purchasers for value having exchanged the money for gambling chips. The House of Lords allowed the solicitors to succeed in debt on the basis that they could trace their money into the defendants’ bank account.