Sweden's Foreign Ministry (UD) has been investigating irregularities at the embassy since the summer, Sveriges Radio reports.
“It's to do with migration questions and involves the handling of visas so clearly it's serious,” UD press head Sofia Karlberg told Sveriges Radio's Ekot show.
Runar Hellström, manager at Sweden's Migration Agency Migrationsverket, explained that improper visa processing could mean for example that visas have been granted despite requirements not being met, or evidently incorrect documents are accepted in processing.
He did not want to comment on the specific cases in Iran, but said improper visa management is always a serious issue.
“It means we end up in a situation where we don't know which foreign citizens are on Swedish soil. It's also an issue for Sweden's credibility within the Schengen area, so it's of course serious,” Hellström explained.