Rebecca Sabben-Clare QC, 49, was identified as the person seen running towards the scene as a passer-by attempted to pull the dog from the nine-month-old puppy, MailOnline reported.
She was then pictured holding the cross under one arm as onlookers tried to help her.
The fatal seal mutilation on the banks of the Thames on Sunday was investigated by police yesterday.
Freddie had to be shot by vets at a wildlife hospital after suffering from a broken fin which meant he couldn’t be released into the wild. A huge uproar ensued, with demands that the dog’s owner be held accountable.
Ms. Sabben-Clare’s attorneys reportedly said the RSPCA and police told her no offense had been committed.
Freddie regularly entertained walkers by sunbathing near Hammersmith Bridge in Barnes, south-west London and his death was marked by a wave of grief on social media.
Floral tributes to Freddie were left at the scene of Sunday’s attack.
Signs on the trees as they approached the slipway read: “Please put your dog on a leash.” Take them away from the seal.
British Divers Marine Life Rescue, whose medics treated Freddie at the scene before taking him to South Essex Wildlife Hospital, said: “We have contacted a number of marine mammal vets… and unfortunately based on their experiences, the decision was that he had to be euthanized for his welfare.