I've got that copy of the Radio Times and it says:
'Patrick Malahide understands the complexity of the role. “Alleyn’s as different as he could possibly be, both professionally and personally, from Chisholm,” he says, referring to his previous incarnation as Det. Sgt Chisholm in ITV’s Minder, who rates rather lower in the charm stakes.'
Personally I think Chisholm has a charm of his own though :-)