Bombs made by arms multi-national Raytheon has been linked to war crimes in Yemen, but the company did not speak to investigating MPs.
At least 443 children in Yemen have been killed or injured in air strikes over the past year, according to a leading global charity.
There have been 366 alleged war crimes in Yemen but only 79 investigations by the Saudi-led coalition - and none by the Ministry of Defence.
American multinational arms dealer Raytheon is part of Fife Science Festival, which is aimed at children.
A report from the Yemen Data Project on the war there found a notable shift in targeting from the Saudi-led coalition with air raids on non-military targets double those recorded on military targets.
Public sector workers will be "shocked and appalled" to learn of the arms industry investments, say critics.
28 firms from Scotland due to attend an arms fair dubbed a “festival of violence” - including a US arms giant with a factory in Fife.
Critics of the arms trade will appeal a High Court decision which allows the UK Government to continue exporting arms to Saudi Arabia.
Raytheon has wined and dined MPs and even treated a minister at the MoD to a slap up Burns Supper with haggis, neeps and whisky.