The Daily Mail said it happened two years ago when Mourinho had been barred from contact with his players during both legs of a quarter-final Champions League tie against Bayern Munich.
He was being punished after indiscretions in the previous round with Barcelona.
On the night of the home leg, observers were convinced that Chelsea fitness coach Rui Faria was using an earpiece hidden under a woolly hat to communicate with the manager, the Mail said.
Both the Mail and The Times said Mourinho arrived early at the ground, watched the game on a TV in a dressing room and delivered the pre-match and halftime talks.
Both papers alleged that about 10 minutes before the end of the game, which Chelsea won 4-2, the manager clambered into one of the laundry skips.
He was then wheeled away to Stamford Bridge leisure club where it was claimed he had spent the entire evening.
Both papers quoted a Chelsea statement saying: "The situation is very clear. Both matches were controlled by UEFA and they were more than satisfied on both nights that their ruling was intact, hence the statements that were issued by UEFA at the time and subsequently.
"The only reason to publish this so close to a big match is to serve an agenda that is intended to undermine our team."
Chelsea play the first leg of this season's Champions League semi-final against Liverpool at Stamford Bridge on Wednesday.
The Daily Mail said UEFA would not be taking up the alleged episode with Mourinho. The Times suggested they were unlikely to act because of the time lapse.
