Police are carrying out inquires into claims two 13-year-old boys were attacked.
Cleveland Police has confirmed an investigation is under way into a report the school boys were assaulted by a man in Seaton Carew.
It comes as Seaton Carew Rugby Club has said it will be carrying out its own inquiry into the incident, which is said to have happened on Saturday afternoon.
A police spokeswoman said: "Police were contacted just after 9pm on Saturday by a member of the public reporting that around four hours earlier a 13-year-old boy and a friend of a similar age had been assaulted by a man in Seaton Carew.
"Initial details were taken and an officer re-contacted the reporting person yesterday.
"Inquiries into this allegation are on-going and anyone with information who has not yet contacted police is asked to ring Cleveland Police via the 101 number quoting Event 48654."
A statement posted on the Seaton Carew RUFC Facebook page by club captain Al Ainsley reads: "On behalf of Seaton Carew Rugby Club I just want to say that as a club we will be doing a full investigation into the assault on the young boy that took place yesterday.
"As it has been mentioned as a possible rugby player being involved, the club takes this matter very seriously.
"We will engage with police to help aide in their investigations in any way we can to help get to the bottom of what happened yesterday.
"On a personal note, I hope that the injuries sustained to the boy aren’t to severe and wish him a speedy recovery. I’m shocked that something like this has happened."
The Mail has contacted the club for further comment.