Michael Brand, 48, was given four months' probation and fined 2,000 by a German court.

Mr Brand offered his kidney for sale over the internet.

But the advertisement, on a German-based auction site, was spotted by a journalist, who called in prosecutors.

Humans can survive with only one kidney

The journalist conducted negotiations with Mr Brand using a hidden camera.

Mr Brand told the journalist he wanted 66,000 euros ($74,500) for the kidney.

He was arrested when prosecutors believed they had gained enough evidence.

Mr Brand said he had been trying to raise money to bail out his girlfriend's business.

"I didn't want to make myself rich," he said.

"I knew it was illegal but not that it was punishable by law," he told the court.

He could have faced a jail term of up to five years.