suspected gas leak?

We were due to have our gas metre changed to a new digital type. my wife mentioned that she could smell gas from time to time. the engineer imediatly stoped work and shut of the gas at the mains (made safe). We susequently had a gas safe plumber to check the pipes. he has said that there is a leak at the gas valve on the boiler which has an automatic pilot. I dont feel that this is the cause of the leak as the boiler is mounted in the kitchen 4 foot high and about 15 foot away from the metre and smell (between 3 doors). Could someone please advise me if this is a logical cause of the leak / smell or is there another posible reason.

many thanks,

Tony Price.