Files released in September 2019 indicated that Houghton, and perhaps Gee, could have been arrested in 1957 but MI5 ignored warnings from his spouse as the "outpourings of a disgruntled and jealous wife." The Security Service finally acted only after it received a tip from a CIA agent who was a mole in the Polish intelligence service. Gee always claimed that she had acted out of affection for Houghton, and that seemed to have been confirmed by letters (also released, in redacted form) that she had written to him in 1962.