The National Crime Agency must explain why it failed to investigate allegations of “credible” Russian money laundering, a joint letter from two MPs has claimed.

The organisation responsible for investigating organised criminal syndicates operating in the UK has been told its bosses should explain to parliament exactly who told a senior officer to abandon any inquiry into a Kremlin-linked operation.

Richard Benyon and Ian Austin, a Conservative and Labour MP, have written to Lynne Owens, the National Crime Agency (NCA) boss, saying they were “shocked” to discover a retired senior officer was told by superiors to “close” any investigation.

Last month, the Telegraph reported that Jon Benton, the former head of the NCA’s international corruption unit, was handed a 37-page dossier produced by Bill Browder, a British financier, alleging money laundering by a Russian crime syndicate linked to the Kremlin.

Mr Browder has run run a long campaign against the Vladimir Putin regime after his lawyer, Sergei Magnitsky, died in a Moscow jail where he had been held after exposing corruption and theft from his businesses.