The Poirot star is lobbying bosses at Britain's National Health Service (NHS) to make treatment more readily available for little known illnesses such as Tuberous Sclerosis Complex (TSC), which his son Richard's child Todd suffers from.

The incurable disease means the star's grandson may develop tumours in organs and suffer from epilepsy and learning or behavioural difficulties.

Suchet is now urging the U.K. government to make vital changes to healthcare and has thrown his support behind initiative #Fight4Treatment to help raise awareness.

He tells Britain's Daily Mail newspaper, "The condition was discovered when he was just a few weeks old when he started having fits. He had an MRI and was found to have TSC. Some people don't discover it until later on in life and it can manifest itself in various different phases. The drugs are available but we can't get them.

"There are many reasons why we don't have access to them but there seems to be such disorganisation and mismanagement in the admin side that it's all gone pear-shaped and people are suffering. #Fight4Treatment is fighting to get drugs for rare diseases and non-rare diseases available from the NHS, to give to sufferers who would benefit. They're so expensive, it's almost immoral."