Rik Mayall was "happily chatting" to the son of British director Peter Richardson only half an hour before he died.
The comedy actor died yesterday, aged 56.
"He was happily chatting away [to my son] and then we still don't know quite what happened but it was a seizure of some sort," said Richardson on BBC Radio 4's Today programme.
In 1998, Mayall was left in a coma for several days after a serious quad bike accident. He recovered, but was left with epilepsy - for which he took daily medication.
"He had 16 years after the quad bike and I think that at the time people didn't think he would survive," added Richardson, who worked with Mayall on The Comic Strip Presents.