The US Department of Justice pushed on Saturday for a court order to isolate certain Alaska ballots to investigate potential voter confusion, while federal officials confirmed the existence of a criminal probe over a Senate candidate Dan J Sullivan who shares a name with the Republican incumbent Dan S Sullivan.

The duelling developments came days before Tuesday’s ranked choice general election, in a race headlined by two-term Republican Senator Dan Sullivan and Democratic former US Representative Mary Peltola. The race is among a handful nationwide expected to determine control of the Senate.