The documents that the Serious Fraud Office (SFO) sent to the wrong person are linked to an investigation into the defence giant BAE Systems.
While it is not clear what the documents relate to, the SFO has investigated the company over contracts it won with several countries including Saudi Arabia, Tanzania and South Africa.
BAE Systems was fined $400 million (£257m) by the US and Britain in 2010 following long-running corruption probes into defence deals around the world.
Last year, the company paid £30 million to the Tanzanian population after failing to keep adequate records of payments it made to receive a defence contract in the country.
More top news
Elise Christie's Winter Olympics ended in dramatic fashion as she crashed out of the women's 1000m before being disqualified.
Bloating is a sign of ovarian cancer, but a poll has found that some women would be more likely to change their diet than visit their GP.
Jeremy Corbyn met Jan Sarkocy in the 1980's leading a number of questions being asked about the Labour Leader in recent days.