The following death notice appeared in the Daily Telegrapy on April 25th, 2012:

CURLE Jon Alfred died 12th April 2012, aged 83, in hospital soon after bowel cancer diagnosed. BBC broadcaster and announcer. Leaves friends and their children who benefited from his cultured generosity. Funeral 2.30 p.m., Friday 11th May, Eltham Crematorium, SE9..—No flowers please ? donations instead to Blackheath Halls Recital Room Lift Fund, c/o Francis Chappell F/D, 5 Thomas Street, London SE18 6HL.

A VERY, VERY dear man, indeed. Always effusively polite to everybody, and the consummate professional announcer!
I had the great privilege of working with him from his time presenting on Radio Two (Night Ride, etc.,) as well as when he'd moved on to Radio 3, in Continuity.
His name brings to mind so many of 'those' voices - Vic Hallam, Tom Crowe, Patricia Hughes, Peter Barker, Donald McLeod, Malcolm Ruthven, Tony Scotland and of course Cormac Rigby. Although it's now some 25 years since my last stint in Con, I can still see and hear them all in my head - and long may it remain so.
I believe his voice can still be heard as one of three announcers (Roy Williamson and Peter Donaldson being the other two) who read the "Billet Doux" prose so often used to test the 'natural tones' of Loudspeakers. [I'm trying to identify which copies of those test discs I've got that include his version!]