Possible Clues:

• The sort of cyanide for a CID at last if it's like this at last
• Relating to sort of blue film about break-up of USSR
• Killer from Portugal caught — arrested by state police
• Sort of acid acceptable around most of vast country
• Deadly acid of copper to engulf huge area shortly
• -- acid, old-fashioned term for hydrocyanic acid
• Broken spurs, I see, will prove fatal with 31 across
• If it's a CID matter it may be a murder matter
• The spur is broken like this, so it may be a CID matter
• Lady¹s exactly so, somewhat acidic?