A downhole cleaning apparatus comprising: a body and a cleaning element coupled to the body; the cleaning element selectively moveable in relation to the body from a retracted position to an extended position; and the cleaning element having an inner portion comprising a first retention formation and an outer portion comprising a cleaning formation ; and an actuation system comprising a second retention formation slideable in relation to the body between a retaining position and a release position; wherein; either: (i) the first retention formation comprises a protrusion from an inner face of the cleaning element and the second retention formation comprises a recess or aperture sized to receive at least a part of the protrusion set into an outer surface of a part of the actuation system; or: (ii) the second retention formation comprises a protrusion from an outer face of a part of the actuation system and the first retention formation comprises a recess set into an inner face of the cleaning element sized to receive at least a part of the protrusion; wherein, in the retracted position, the first retention formation is coupled to the second retention formation; and wherein the first and second formations together function as a latch, to latch the cleaning element in the retracted position; the first and second retention formations being slideably releasable from one another by sliding the second retention formation from the retaining position to the release position, in which the cleaning element is able to move to the extended position. a body and a cleaning element coupled to the body; the cleaning element selectively moveable in relation to the body from a retracted position to an extended position; and the cleaning element having an inner portion comprising a first retention formation and an outer portion comprising a cleaning formation ; and an actuation system comprising a second retention formation slideable in relation to the body between a retaining position and a release position; wherein; either: (i) the first retention formation comprises a protrusion from an inner face of the cleaning element and the second retention formation comprises a recess or aperture sized to receive at least a part of the protrusion set into an outer surface of a part of the actuation system; or: (ii) the second retention formation comprises a protrusion from an outer face of a part of the actuation system and the first retention formation comprises a recess set into an inner face of the cleaning element sized to receive at least a part of the protrusion; (i) the first retention formation comprises a protrusion from an inner face of the cleaning element and the second retention formation comprises a recess or aperture sized to receive at least a part of the protrusion set into an outer surface of a part of the actuation system; wherein, in the retracted position, the first retention formation is coupled to the second retention formation; and wherein the first and second formations together function as a latch, to latch the cleaning element in the retracted position; the first and second retention formations being slideably releasable from one another by sliding the second retention formation from the retaining position to the release position, in which the cleaning element is able to move to the extended position. <EOS>