A retired British businessman accused of conspiring to sell missile parts to Iran was extradited to the United States on Friday, but branded his treatment a “disgrace”.

Speaking to reporters as he arrived at London Heathrow airport, where he was taken into custody by US marshals, Christopher Tappin protested his innocence and said he should have been tried in Britain.

US prosecutors accuse the 65-year-old of attempting to unlawfully export batteries for surface-to-air missiles, which were allegedly due to be shipped from the US to Tehran via The Netherlands.