May have been earl of Gowrie.
See Alasdair Ross, 'The Identity of the Prisoner at Roxburgh: Malcolm son of Alexander or Malcolm Macheth?', in Sharon Arbuthnot and Kaarina Hollo (eds), Fil Súil nGlais: A grey eye looks back. A Festschrift in Honour of Colm Ó Baoill (Ceann Drochaid, Brig o Turk, 2007), pp. 269-82.