Sri Lankan Government’s special inquiry committee have summoned Kumar Sangakkara, Mahela Jayawardene, Aravinda de Silva and Upul Tharanga for the 2011 WC match-fixing investigations which happened on Wednesday. Earlier, Mahindananda Aluthgamage had alleged that the final was fixed.
After the fixing claims by former Sri Lankan sports minister Mahindananda Aluthgamage, who was seeking re-election in parliamentary polls next month, Sri Lanka's Sports Ministry set up a special investigation unit even though ICC's Anti-Corruption Unit (ACU) never stated that the final was under suspicion.
As per a report on ESPN Cricinfo, Aluthgamage's allegations appear to be about the four changes Sri Lanka made to their XI for the final. While Sangakkara, Jayawardene and de Silva, who was chief selector, have repeatedly said that those changes were precipitated by injuries to Angelo Mathews and Muttiah Muralitharan sustained during the semi-final.
As far as the legality of asking those players to appear before the special inquiry commission, this was a part of the Sri Lankan sports bill under the section "Prevention of offences related to sports act". The bill was passed last year with the aim of curbing fixing and ICC's ACU worked closely with the Sri Lankan government during the drafting of that bill.