The US Justice Department has escalated its investigation into the candidacy of an Alaska Senate candidate with the same name as the Republican incumbent, Dan Sullivan, issuing more than 40 subpoenas and requests to preserve documents with more expected, a source familiar with the matter told Reuters on Thursday.

Recipients of the subpoenas included the campaigns of Republican challenger, Dan J. Sullivan, and Democratic nominee Mary Peltola, the source said. The New York Times reported on Wednesday that Peltola’s campaign was involved in recruiting Dan J. Sullivan into the race.

(Reporting by Andrew Goudsward, editing by Bhargav Acharya)