The club have been barred indefinitely from playing matches at their home stadium, with the new LaLiga season just three weeks away, due to the potential risk of supporters contracting Legionnaires' disease.
Rayo rent their stadium from the regional government of Madrid, but have seen their licence suspended, after an audit highlighted serious health and safety issues, plus increased fire risks.
The issue has been at the centre of long-standing issues between fans and club owner Raul Martin Presa with the team unsure when or where they will play home games this season.
Photos at the stadium show discarded rubbish bags, bottles of liquid fertiliser, cardboard boxes, plastic packaging, paint cans and other objects piled up in the stands and in the outside.
Last season's UEFA Conference League finalists have come under fire after their average season ticket price increased by 15% for adults with fans now line for a refund.
Reports from Diario AS claim the clean up operation has now been blocked, after a team of staff deployed by local authorities were denied access to the stadium, and the operation could last until the end of 2026.
The team are currently away on a preseason tour with their first home match scheduled for August 20 against Alaves.