The doctrine of estoppel does not apply to bar a claim for the recovery of money paid under a mistake of fact if the recipient of the money has changed his position to his detriment before the mistake is detected.

( 1 ) THIS appeal is at the instance of the plaintiff United Bank of India Limited and it arises out of a suit for recovery of money.

( 2 ) THE case of the plaintiff was that on January 14, 1957, the defendant no. 2, the Union Bank of India Limited, presented to the plaintiff bank, a cheque for Rs. 5,200/- bearing date January 11, 1957 purported to have been drawn by the Metal Alloy Co. Private Ltd. , a constituent of the plaintiff bank, in favour of the defendant no. 1, A. T. Alihussain and Co. and crossed "not negotiable and account payee only". The plaintiff bank, acting under the mistaken belief that the said cheque had in fact been duly signed by the said Metal alloy Co. paid the said sum of Rs. 5,200/- to the defendant Union Bank by debiting the C/d Account of the said constituent. The signature on the said cheque and all other writings appearing thereon had, since transpired, been forged and no one on behalf of company had signed or drawn the same. The forgery of the said cheque along with two other cheques were the subject-matter of criminal proceeding and in that proceeding one Prodyot Kumar Ghosh and another were convicted. On February 22, 1957, the plaintiff, after making necessary enquiry, came to know that said cheques were forged and the amounts covered by them were obtained by fraud on the plaintiff who paid the same by mistake. Thereafter, on March 4, 1957 the plaintiff made a payment of Rs. 14,800/- being the total amount covered by the aforesaid three cheques including the cheque in question to its said constituent, the Metal Alloy Co. , on demand being made therefore. It was claimed by the plaintiff that the defendants nos. 1 and 2 were liable for the amount covered by the cheque in question, that is Rs. 5,200/- paid by the plaintiff as aforesaid. Accordingly, the plaintiff prayed for the recovery of the said sum of Rs. 5,200/- from the defendants.

( 3 ) THE suit was contested by both the defendants. The case of the defendant no. 1 was that certain persons alleging to be the representatives of the Metal Alloy Co. Pvt. Ltd. , of Asansol came to the defendant's show room on January 13, 1957 in order to ascertain the price of certain tube-well materials and after such talks and ascertainment of the price, they came on the next day with a cheque for Rs. 5,200/- and the defendant, in the ordinary course of business entered the order placed by them in the order book. The defendant acting in good faith sent the cheque to it banker, namely, the Union Bank of India Limited for collection, and after the cheque had been encashed delivered the goods to those persons on January 15, 1957. it was asserted by the defendant that it had acted in good faith having no reason to suspect that the cheque was forged, and on receipt of an intimation from the defendant bank, it parted with valuable properties and were not, therefore, in any way liable for the alleged loss suffered by the plaintiff. It was contended by the defendant that the plaintiff and its constituent had acted negligently and carelessly, and that accordingly, the plaintiff was precluded from recovering the money form the defendant.

( 4 ) THE case of the defendant no. 2, the Union Bank of India Limited was that in the ordinary course of business it received the cheque in question on or about January 14, 1957 and in good faith presented the same for encashment which the plaintiff bank duly honoured. It was contended that the plaintiff bank was under a duty to ascertain the genuineness or otherwise of any cheque drawn by its constituent and if it had allowed any forged cheque to be encashed it would have to suffer the loss arising from its conduct.

( 5 ) THE suit was tried by the learned Judge, Sixth Bench, City Civil Court, Calcutta. He came to the finding that the forgery of the signature in the cheque had been so accurately done that it was not possible even to a trained eye to detect the forgery. The contention of the defendants that the plain