A seal first spotted off the Norfolk coast more than two years ago with a plastic disc stuck around her neck has been nursed back to health.
She has been released back into the wild after being rescued in the spring.
The seal, nicknamed Mrs Vicar by volunteer rescuers due to the white disc around her neck, was caught at Horsey Beach and freed from the plastic at the RSPCA’s East Winch Wildlife Centre near King’s Lynn in April.
Discs can become caught around the animals’ necks, cutting into them as they grow bigger.
The 2.5cm-wide rigid plastic ring, thought to be used in large-scale pipework, had caused Mrs Vicar a 7cm-deep wound which became infected.
An RSPCA spokesman said it was the worst injury of its type that the charity had seen.
Mrs Vicar was given salty baths to help the wound to heal and after three months at the centre she was strong enough to return to the wild.
She was released into the River Nene at Sutton Bridge in Lincolnshire on Tuesday, so she can make her way back to the North Sea.
The adult grey seal was finally captured at Horsey Beach in Norfolk on Easter Sunday after more than two years in the wild with the ring stuck around her neck.
Volunteer rescuers from Friends of Horsey Seals caught her and a vet removed the plastic.
Ben Kirby, interim centre manager at RSPCA East Winch, said: “The wound on Mrs Vicar’s neck will always be very visible and is a sad reminder of how much damage plastics in our seas can cause to the natural world.
“The vets and staff at East Winch have worked incredibly hard to rehabilitate this special seal so that she could one day be returned back to the wild.
“While the scars around her neck will always remain, the salt water will continue to heal her neck.
“She’s now a healthy weight and we’ve done all that we can for her – it’s now up to her.
“Since day one she has just fought and fought to survive and never gave up, despite how sick she was.
“We just all feel so proud to have been able to help her with this second chance.”
Alison Charles, former centre manager at RSPCA East Winch who has since retired, previously said: “When I first saw how severe Mrs Vicar’s wounds were I was really worried she wouldn’t be able to make it.
“It was just so severe and infected and you could smell the infected flesh, it was just awful.
“When the ring was removed it then meant that her body released a huge swell of dangerous toxins, which she then had to fight off.
“So for the first few days she didn’t really move or show any signs of improvement – and although this is something we do see with necklace-injured seals, it was still very worrying that she wasn’t going to pull through.
“However each day there was a small sign of improvement and she started eating and her salt baths began to work on the infected wound.”
Several weeks into her recovery Mrs Vicar was moved to an outside pool where staff built up her strength by getting her to swim from one end to the other for fish.
At least three seals have had similar discs caught around their necks in recent years.