Twitter is responsible for almost half of the child abuse material found by UK investigators being hosted openly on popular tech sites, according to figures seen by the Telegraph.

Statistics from the Internet Watch Foundation (IWF) show that 49 percent of the images, videos and url links it found on social media, search engines and cloud services in the last three years were on the social network, making up 1,396 of the total 2,835 incidents found.

Child protection figures warned the each incident could represent hundreds or thousands of images or videos, as they included urls linking back to child abuse websites.

The IWF, the UK's online abuse watchdog, can only find child abuse material on the open web, meaning all the abuse images and videos found had slipped through tech companies' filters and were available for anyone to see. The IWF is also unable to scan for abuse images in messaging apps or even closed Facebook groups.

The IWF say that the figures show the number of child abuse images and urls being openly hosted on popular sites was increasing year-on-year, with 742 incidents found in 2016, 1,016 in 2017 and 1,077 in 2018.

John Carr OBE, secretary of the Children’s Charities' Coalition for Internet Safety, which represents organisations such as the NSPCC and Barnardo's, said: “It is appalling and scandalous that thousands of child abuse images are openly available on popular social media and search engine sites for anybody to see.