Arms firms in Scotland are failing to make human rights checks which could prevent their products from being used in potential war crimes.
Arms firms due to attend a trade event dubbed a “festival of violence” gave MP's more than £60,000 in donations.
The UK government has been condemned for arming states named in a UN report revealing that 12,000 children were killed or maimed last year in armed conflicts.
Bombs and missiles will still be exported to Saudi Arabia under a secretive licensing system despite a court ruling that UK arms sales are illegal.
The UK government broke the law by selling arms to Saudi Arabia, the Court of Appeal says in a landmark ruling.
Arms firms supplying weapons for the war in Yemen that has killed 70,000 people were handed nearly £3m by the Scottish Government last year.
Investments worth nearly £130m were made in arms firms linked to Yemen's conflict, which has left an estimated 70,000 people dead.
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.