NEW YORK, July 23 -- Inter Miami said Wednesday it completed the signing of Brazilian midfielder Casemiro as a free agent, adding one of the biggest names in world football to a squad that already features Lionel Messi.

The announcement was followed by news that the MLS had launched an investigation into alleged irregularities involving the move.

Inter Miami said the 34-year-old, who left Manchester United in June, agreed to a contract that runs until the end of 2027, with an option to extend to June 2029.

Casemiro confirmed in January that he and United had mutually decided to part ways after four years. In its statement, Inter Miami said it had obtained Casemiro's discovery rights from LA Galaxy as part of the transfer.

Under MLS ru...