Marriage trouble for Madonna and Ritchie?

Talk of a "special" relationship with her producer has sparked fresh fears over Madonna's marriage.

The singer was apparently caught leaving collaborator Stuart Price's flat after spending nearly three hours there behind closed blinds.

Friends told the Daily Mirror about the pair's close link. "It's no secret that Madonna and Stuart have developed a special working relationship," said one. "Madonna's always asking Stuart's advice and opinions on things and obviously trusts him without question. She confides in him and regards him as one of the most important people in her life."

Meanwhile, Guy's friends told the paper that he is finding the marriage difficult. "He feels totally hemmed in by her career at the moment. It's as if work is the only thing that interests her," commented one. "He's spending a lot of time at home alone, except when the children are around."

Both have talked about difficulties with their relationship in the past. Madonna once said of the producer: "I couldn't stop thinking about what fun it was to work with Stuart. It took me a minute to decide which boyfriend I wanted to have."