According to the LSE, the two outage crash which occurred on the platform in November of last year was not due to sabotage as it had claimed at the time.
When the Turquoise platform went down, the LSE speculated that it had taken place in suspicious circumstances and called on both the Financial Services Authority and the police to launch investigations.
In a statement, the LSE said: âThe exchange can confirm that its internal investigation into last November's trading disruption on Turquoise has now concluded.
"The investigation found the incident was the result of human error and the incident has now been closed.â
The LSE has unveiled a revised plan for the transferral of its trading to a new platform - the migration to the MillenniumIT trading system is now taking place on February 14th after originally being scheduled in December of last year.
Dress rehearsals for the transition are expected to take place on January 29th and February 5th.
By Jim Ottewill