Rangers at Bradgate Park are urging visitors to use on-site bins or take litter home after a cygnet was found with string caught around its beak and foot, making it unable to eat.
The Trust says the rangers managed to catch the cygnet and remove the string.
On a Facebook post the Bradgate Park Trust said: "This cygnet was found with string caught around it's beak and foot making it unable to eat.
"Fortunately our rangers managed to catch it and remove the string.
"We urge visitors to use our on site bins or take litter home.
"Please take care of the park and its wildlife and do not litter."