Chris Cash says he was a convenient fall guy in collapsed China spying case

Chris Cash, a former parliamentary researcher, has told the BBC he became a convenient fall guy for UK police and security services that wanted to put espionage threats by foreign states on the map. It was his first interview since the spying case against him and Chris Berry collapsed last year.

Cash, then 27, was asleep at his parents' house in Scotland when four counter-terror police officers arrested him on suspicion of spying for a foreign state. He had met Berry while teaching English in China. Berry stayed when Cash returned to the UK, and the two kept in contact after Cash took a job with a China-sceptic group in Parliament.

Cash gave the BBC a tranche of messages between the two men, put at more than 6,000 in the BBC's introductions and 6,000 or so in Joe Pike's report. They were central to the prosecution case and had not been seen in full before. His solicitors confirmed they were genuine. The messages contain no evidence that Cash was paid by, or was sympathetic to, the Chinese Communist Party, but the pair discussed sensitive subjects including sanctions, Taiwan and Hong Kong. Cash said much of the material was already public and described his conduct as naive, unprofessional and stupid.

Berry messaged Cash about a secret meeting with a senior Chinese government official. Berry later said the man was Cai Qi, who has since become, in effect, President Xi Jinping's chief of staff. Berry has disputed that he met someone that senior. Cash said he had no idea at the time who the official was. After the meeting Cash told Berry, "you're in spy territory now", and said the remark was a tongue-in-cheek joke. He also told Berry to "keep him sweet, we may have use for you yet" and joked about spying for the UK.

Prosecutors dropped the spying charges last year because they said they could not get the UK government to confirm China was an enemy. Ministers believe new, tougher laws would now make such a prosecution easier. Cash said he understood police and security services wanted to put Chinese espionage or state threats on the map, but that he became the convenient fall guy for everyone.

Chris Berry declined to comment. He has previously denied wrongdoing and said his reports contained issues widely discussed and information in the public domain. China has called the allegations malicious slander.

In a live interview, BBC News's Joe Pike said the messages were a large tranche and much of it was mundane, including memes, jokes and links to political podcasts or news articles. He said they also contained sensitive information about UK foreign policy, human rights, Taiwan, Hong Kong and Huawei. Not all of it was public: BBC News reported that the messages recount a visit to Parliament by the UK's ambassador to Beijing and her views on the work and research focus of the parliamentary group Cash worked for.