LJUBLJANA (AFP) - A Slovenian doctor was in custody on Thursday on suspicion of having killed at least seven terminally-ill patients, authorities said.

"After a very thorough investigation, we believe there are reasonable suspicions of several crimes committed by the accused," state prosecutor Katarina Bergant said.

The Ljubljana Clinical Centre Hospital doctor was fired last year for allegedly intentionally killing an 83-year-old terminally-ill patient without his consent.

He was not charged over that death but a subsequent police probe uncovered other suspicious deaths allegedly attributable to the doctor.

Website 24ur reported on Thursday that he attempted suicide on Wednesday with a piece of broken glass and has been moved to hospital for his own safety.