Chelsea have begun an investigation into allegations of historical sexual abuse concerning an individual, now deceased, who was employed by the club in the 1970s.
The news comes as more than 20 ex-footballers have made allegations of child sex abuse, with several police investigations also underway.
A statement from Chelsea on Tuesday said: "Chelsea Football Club has retained an external law firm to carry out an investigation concerning an individual employed by the club in the 1970s, who is now deceased.
"The club has also contacted The FA to ensure that all possible assistance is provided as part of their wider investigation. This will include providing The FA with any relevant information arising out of the club's investigation.
"The FA has commissioned a dedicated NSPCC helpline for adults who were victims of sexual abuse in childhood within the football industry. The helpline is available 24 hours a day on 0800 023 2642.
"While the club's investigation is ongoing, we will make no further comment on this matter."
There have been 250 reports made to police and more than 50 calls were made to an NSPCC hotline set up for sexual abuse victims in football in the initial hours of opening.