Can't find gas leak

[Truetoself]

Has anyone had a gas leak that the engineer was unable to isolate? He just turned the gas off and said our options are either to dig up our floors/ walls so they can check the pipes or run a new pipe. Luckily the boiler is outside the house and our gas hob is on an external wall. No idea how to get gas to the gas fires in the centre of the house.
We have another heating engineer coming out for a second opinion tomorrow but just wondering what I can expect or is there anything I can ask them I haven't thought of?

Hi OP

What a nuisance! Good thing it’s turned a bit warmer.

Did he check :

gas lines into the house
gas connections
appliance valves

Perhaps he didn’t have all the equipment and the chap tomorrow will fare better.

Hope you get it done.

Was it the supplier or a local plumbing and heating engineer? If it was the latter I would call the gas board.

So the person who came out initially was from SNG who attends to emergencies.
The second person was from british gas homecare.
I feel we are at their mercy wrt outcome.

@SerenStarEtoile no he was focusing on the room where gas was smelt.

When I had a gas boiler fitted - British Gas identified a gas leak in the pipe that leads to the gas fire in the living room. Floor was solid concrete and the pipe buried in it(1960s build) The option was to run a pipe around the house to provide a connection, dig the floor up or replace with an electric. I went with an electric fire.

@Gunz yes we may need to consider the same