Authorities in the German city of Muelheim spent 100,000 euros ($133,700) on a three week mission to recover a missing snake -- only to discover it had died.

"We had to do everything in our power to find this cobra," said Volker Wiebels, spokesman for the city council.

After the highly poisonous monocled cobra escaped from its container in March, fire services cleared the entire apartment block, removed all the furniture and gutted the owner's flat.

They then sealed all the doors and windows of the building, so the 30 cm (1 foot) long reptile couldn't get out, and set large sticky traps to catch it, Wiebels said.

Officials finally found the snake lying dead in the rooftop apartment of its 19-year-old owner Thursday. By that time the cost of the operation had ballooned to about 100,000 euros. Taxpayers are likely on the hook for 40,000 euros, because an escaped snake is considered public hazard, Wiebels said.

The rest falls on the owner, who paid 70 euros for the snake at a local reptile trade fair. It was unclear if the city would get its money back, because the man is currently unemployed.

"The snake may have been cheap, but unfortunately what happened next wasn't," Wiebels said.