A potentially deadly king cobra has gone missing again - only hours after being tracked down from a previous escape.
The snake housed at Skansen Aquarium in Stockholm's Djurgarden island zoo sparked a closure of the attraction last week when it suddenly disappeared from inside its enclosure.
After six days of frantic searching, the evasive reptile was eventually found by authorities and placed in a supposedly secure enclosure in the park.
But it has since made another bid for freedom, with zoo staff now waiting to attempt a second recapture after isolating him within the terrarium area.
The snake, nicknamed 'Houdini' though officially called Sir Vass (Sir Hiss), had only recently arrived at the park when he went missing for the first time.
It is thought he had squeezed himself out of a gap located around new energy-saving bulbs installed inside the enclosure.
Skansen zoo, which has housed king cobras for almost 15 years, had previously used an older model of lightbulb thought to have prevented previous escapes by emitting heat.
Speaking at the time, Skansen Aquarium director Jonas Wahlström told AFP: "He won't come out - in theory, it's so cold outside that he would fall asleep"
"He must be a smart guy. The old lamps were too hot, which kept the snakes away."
Customs officers eventually found the snake on Friday after bringing X-ray machines and wire cameras usually used in drugs busts, to trace him inside a wall cavity at the zoo.
"Thanks to methodical work, Sir Väs could finally be located in a middle wall near the terrarium", the agency said in a statement.
But they confirmed that he had disappeared for a second time on Friday, leaving zookeepers to begin their work again.
King Cobras range from 3 to 5 metres, making them one of the biggest snakes found in the wild as well as being one of the most poisonous.
