Transporting cremated remains

I've done a bit of searching but there seems to be answers all over the place (in regards to the airlines themselves). Does anyone know if the Uk has any specific laws on transporting cremated remains? I have 2 (very small ie under 8 oz each) urns of both my mother and father. Of course, I want to bring them with. The airlines seem to be all over the place on requirements, but I'm thinking placing them both in my checked luggage should work. What I can't seem to find is if the UK has any documentation that they require to be filled out.  I would take them in my carry on, however, neither container would be able to be scanned through the X-Rays. I'll have death certificates for both, but i may only be able to obtain any crematory documentation for my mom (since she passed away earlier this year). Sadly, my dad's are for nearly 20 years ago.

Any insight on this would be great!

Thanks everyone.

I found this on the .gov site.

Bringing ashes home
When leaving a country with human ashes you will normally need to show:

the death certificate
the certificate of cremation
Each country has its own rules about departing with human ashes and there may be additional requirements. Contact the country’s British consulate, embassy or high commission for advice. You’ll need to fill in a standard customs form when you arrive home.

Contact your airline to find out whether you can carry the ashes as hand luggage or as checked-in luggage. They may ask you to put the ashes in a non-metallic container so that they can be x-rayed.

https://www.gov.uk/after-a-death/death-abroad