Singapore authorities said they launched an investigation into Citadelle Corporate Services, Senjo Group and its subsidiaries after scrutinising collapsed German payments firm Wirecard's local operations.

The investigation was for "suspected falsification of accounts," and "for carrying on a trust business without a licence", the Commercial Affairs Department (CAD) - the police unit that deals with white collar crime - and the Monetary Authority of Singapore said in a statement on Friday.

Emails sent to Senjo Group and Citadelle to the addresses listed on their websites could not be delivered. Wirecard said it was not making any statements at this time.

Last week, the central bank (MAS) said it is working with the CAD to scrutinise Wirecard's local operations.

"The review surfaced reasons to suspect that offences may have been committed," the authorities said on Friday.

As part of the investigation, CAD and MAS have obtained documents and records from Citadelle and Senjo, and have interviewed persons involved in the companies.

Senjo's website says it is a payments operator, while Citadelle provides company formation and administration services.

(Reporting by Aradhana Aravindan and Anshuman Daga; editing by John Stonestreet and Louise Heavens)