Original sentence: Other allegations included involvement of rogue FSB members or suggestions that Litvinenko was killed because of his research of certain Russian corporations or state officials, or as a political intrigue to undermine president Putin.Shortly after the incident, Russian government dismissed allegations of FSB involvement in the assassination using the argument that Litvinenko was "not important" and "mentally unstable", implying that the government had no interest in killing such an insignificant figure
Edited sentence: Other theories included involvement of rogue FSB members or suggestions that Litvinenko was killed because of his research of certain Russian corporations or state officials, or as a political intrigue to undermine president Putin.Shortly after the incident, Russian government dismissed theories of FSB involvement in the assassination using the argument that Litvinenko was "not important" and "mentally unstable", implying that the government had no interest in killing such an insignificant figure