A Swedish man arrested on charges of unauthorised possession of nuclear material after trying to split atoms in his kitchen says he was only doing it as a hobby.

Richard Handl said he had the radioactive elements radium, americium and uranium in his flat in southern Sweden when the police showed up.

He said on Wednesday he had always been interested in physics and chemistry and "just wanted to see if it was possible to split atoms at home".

Handl kept a blog about his experiments, describing how he created a small meltdown on his stove.

Only later did he realise it might not be legal and sent a question to Sweden's radiation authority, which sent the police.

Detectives have declined to comment on the raid, which took place in late July. If convicted Handl could face fines or up to two years in prison.