Throughout the two days that the whale was in the Thames waters, there were unconfirmed sightings of a second whale near the Thames Barrier and in Southend-on-Sea. On 21 January, whale song was reported around the Thames Estuary. The body of a small marine mammal - later confirmed as a porpoise - was discovered upstream at Putney the same day. There is no indication that this incident had any connection with that of the Thames whale. There had been reports of a harbour porpoise in the Thames near Chiswick and Kew on the Tuesday and Wednesday prior to the Thames whale. BDMLR medics did several watches to no avail; the body of this porpoise washed up nearby on the same day as the whale rescue.