A potentially deadly black widow spider has been found in a crate which had been transported to Scotland from America.

Workers at the business park in Portlethen, Aberdeenshire, were shocked to discover the arachnid lurking in the crate.

They called the Scottish SPCA on Thursday after finding the spider, whose venom is said to be 15 times stronger than that of a rattlesnake.

The charity said the spider had to be "put to sleep" because there was nowhere in Scotland it could be safely kept.

Scottish SPCA chief superintendent Mike Flynn said: "We can confirm we were alerted to a black widow after it was found in a crate from America.

"Bites from the black widow can be dangerous to humans and can cause severe muscle pain and muscle spasms.

"Sadly the spider had to be put to sleep as there is nowhere in Scotland to safely rehome it, and we could not keep it in our centre due to severe health and safety concerns."

In May 2013, employees at a company on Kirkhill Industrial Estate in Dyce, Aberdeen, spotted a stowaway in a shipment from the US and contacted the Scottish SPCA.

It was rehomed by someone who ran an exotic animal rescue charity.

Black widows live for about two years and are native to the US.

Their venom causes cramps and fever although their bites are rarely fatal because of the small amount of poison released.