SHARJAH, Nov 6, 2011 (AFP) - Scotland Yard had stopped Pakistan cricket authorities from taking any action against players involved in the spot-fixing scandal, fearing it may have prejudiced any criminal enquiry, a report seen by AFP revealed on Sunday. Former Test captain Salman Butt received 30 months, Mohammad Asif 12 months, Mohammad Aamer six months and their agent Mazhar Majeed 32 months in prison for their roles in fixing part of the Lord's Test against England last year. The scandal, which rocked the cricket world, surfaced only after a sting operation by the now defunct British tabloid News of the World in August last year. Scotland Yard raided Pakistan's team hotel in London and interrogated the players before allowing them to leave the country only after assurances from Pakistan authorities they would return for further investigation. The Assistant Commissioner of Scotland Yard wrote a letter to the then chairman Pakistan Cricket Board (PCB) on September 1, 2010 asking them not to take any action against the players. The PCB has come in for serious criticism from former players and analysts for not taking any action, but the letter -- a copy of which has been seen by AFP - stopped the authorities from taking any action. "As you know we took the decision not to arrest any of the players when the enquiry commenced, a key part of that decision was that the players would make themselves available for interview at our request," said the letter. It added: "I am fully aware of how seriously you are treating these allegations and understand that you will wish to take your own action in response to them. "However, as I am sure you are aware, in the UK a police investigation takes precedence over any civil or disciplinary matters and I ask that you do not take any action that may prejudice any criminal enquiry. "Action that could prejudice a future criminal prosecution could include interviewing players or witnesses or taking any account from them relating to the matter under investigation." Independent sources said the players continued to be with the squad as the investigations were on. "As per Scotland Yards letter since the PCB could not initiate any enquiry therefore players on their own gave in writing to the PCB that since their name is involved in the police investigation therefore till the time it is cleared they should not be considered for selection during the series." "Since the players could not leave the UK (any attempt would have resulted in immediate arrest) the three players went to Taunton as per the schedule," the sources said. "There was also a matter of security and media following the players," said sources. Pakistani government also assured Scotland Yard that the players under investigation would return to the UK for any further enquiry if that was what was required.