Madonna has set up a "sterilisation team" to wipe away any DNA in her dressing room after shows on her MDNA world tour.

The 53-year-old has also told organisers only her and her entourage are allowed ­backstage passes.

Concert promoter Álvaro Ramos, who is overseeing the Portuguese leg of the concert dates revealed her demands.

Speaking at a press conference, he said: "We have to take extreme care, like I have never seen for any other artist. We cannot even look at the dressing room, after it is ready, or even open the door.

"We can only enter after her sterilisation team has left the room. There will not be any of Madonna's DNA, any hair, or anything. They will clean up ­everything. In the end it is all to protect her and make her feel comfortable.

"I do understand it, but it is taken to extremes."

Madonna's other demands in the past have included ordering a new toilet seat at every venue.

The singer will play at the Coimbra City Stadium in Portugal, where the dressing rooms will be converted by her own staff.

Álvaro added: "Her team will build everything for her, including fake ceilings and fake walls, so they can ensure that no one has hidden a camera somewhere."

Last night, a source close to Madonna said: "She is a ­perfectionist, and expects the best. But then, at her age and with her status, why shouldn't she?"