<h1>Investigators summon eight people linked to singer's yacht death; four associates arrested, MLAT used for foreign evidence</h1> A state chief minister said investigators have summoned eight of the 11 people present with a deceased singer on a yacht; one summoned person has responded while seven have not. Four associates, including the singer's manager and festival organiser, are arrested and in custody. Authorities rely on Mutual Legal Assistance Treaty channels with the foreign jurisdiction for evidence and say local police need not conduct on-site probes abroad. Central agencies have been asked to examine festival-related finances. Calls for a federal CBI inquiry were criticized as politicizing the death. The government stated autopsy reports cannot be publicly released but certified copies are obtainable through the court.