At around the time Agar had separated from Kay, he met Emily Campbell, a 19-year-old prostitute, and the two began a relationship; Campbell's pimp, William Humphreys, took umbrage at the loss of her earnings. To overcome any problems, Agar lent Humphreys £235. When he went to collect the repaid money, he was arrested as one of Humphreys's associates passed him a bag of coins. Police stated that this was the proceeds of a cheque fraud in which he was involved and he was charged accordingly; Agar stated he knew nothing of the fraud, and he was trying to collect the money he had lent. Appearing at the Old Bailey in September 1855 on the charge of "feloniously forging and uttering an order for the payment of 700"L" [£700], with intend to defraud", Agar was found guilty and sentenced to penal transportation for life.