Ollie, who has lived at Long Melford Country Park for nearly 30 years, was taken to Wildlives Rescue and Rehabilitation Centre after concerns about his health.
People linked to the park criticised the decision, saying it had separated Ollie from his long-term partner, Vera, and could cause him severe stress.
Ollie was removed from the park by Wildlives Rescue and Rehabilitation Centre.
In a Facebook post, the park said: “This is the first time he has ever been removed from his home and his partner in his nearly thirty years.”
The park added that Ollie was “very, very old”, suffered from arthritis and had been walking badly for several years after being victim to a number of dog attacks in the park.
The park said on Tuesday that Vera had not been seen that morning or the previous night.
Wildlives defended its intervention, saying Ollie made no attempt to stand when volunteers arrived and had “extensive swelling and heat” around his left leg joints.
The centre said: “Ollie has sustained trauma to his leg at some point, which, left untreated, has resulted in a severe infection that has spread into his knee joint, causing him considerable pain.”
The centre said Ollie was receiving antibiotics, painkillers and anti-inflammatory drugs and was already moving more freely.
The park questioned why it or Melford Parish Council had not been contacted before Ollie was removed.
Ollie at the rescue centre with another swan who was rescued from Sudbury.
Susie Dixon, the parks wildlife contact, commented online: “You actually had no reason to take Ollie from Melford Country Park. He was being watched by local vets.
“His only problem is old age, but you took him from Vera, his long term partner and cygnets and now they are distraught.
“Moving him out of the home he has had for nearly 30 years without consulting Melford Parish Council was rash and stressful for Ollie, Vera and the whole much loved swan family.”
Wildlives said its volunteers had also received abusive calls and messages over the rescue.
“We understand that people who know and love Ollie are upset and concerned about him,” it said. “However, abuse directed at the people trying to help him is neither fair nor acceptable.”
Wildlives said Ollie would be reunited with Vera and his family when he was well enough.
Wildlives Rescue and Rehabilitation Centre and Long Melford Parish Council were approached for comment.