my freelander mk1 diesel keeps cutting out

new member,can any one help me?my wife has a yr 2000 diesel freelander mk1,shes had it for 12 months and its run fine up until now.whilst driving it the other day she came to stop at a junction heard a buzzing noise then the engine stopped,some kind gents pushed her to the side of the road,she tried it again and it started,drove on for couple of miles and it cut out again.when it started she dropped it off at the local garage who drove it to the moon and back but it never cut out again.so i drove it to work this morning going round a roundabout and it just cut out.it started after a couple tries then at low revs turning a corner it did it again.filter?fuel pump?auto electrician?does anyone have any advise for me on where i start?and dont reply with petrol and a match because the garage has sold out!many thanks.andy71