A collecting device for displacement in a tubing. The collecting device is extended in shape with a longitudinal axis and forms a leading portion with an entrance and an end portion. The device includes a wall extending from the leading portion to the end portion, a collecting chamber formed inside a portion of the wall, a filter positioned with the collecting chamber, a motor, a pump, and an outlet at the end portion, where the filter stocking provided with an open first end portion and a closed second end portion, and the open first end portion faces the leading portion, a and the filter stocking forms a receptacle. A method for emptying the collecting device is described.