A Chesterfield gym is currently closed.
Princes Sports Club on Old Road, Brampton, shut unexpectedly on Thursday.
A number of paid-up members of the gym have contacted the Derbyshire Times to voice concern about the situation.
In a statement issued on Thursday night, Stephen Prince, owner of Princes Sports Club, said: "You may be aware that the Princes Sports Club has been closed today.
"This is due to an ongoing legal issue with a third party which has been brought to a head today.
"My management team and I are not at liberty to discuss the details, however, please be assured that our decision to stand our ground over the matter is to ensure that the club and everyone's investment in the club remains secure.
"This situation is unexpected, heavy handed and forced upon us without negotiation. I sincerely apologise for any distress and inconvenience that this may be causing. We are hoping for a speedy resolution so that we may all resume our normal activities at our club.
"Thank you for your support, it is very much appreciated."
'Forfeiture of tenancy'
A 'forfeiture of tenancy' notice has been put up at the premises.
The notice states: "Under the conditions of the implied periodic tenancy of these premises held by the tenant, rent due has not been paid to the landlord.
"The premises have been recovered by the landlord."
The notice states that the tenant is Public Sector Consultants Ltd, which is owned by Mr Prince.
Mr Prince told the Derbyshire Times he could not comment on the notice at this stage.
He added: "I have a meeting to discuss re-opening ASAP, but this is dependent on the site landlord's response to any proposals we make."