ZURICH/SINGAPORE (BLOOMBERG) - UBS Group flagged suspicious transactions linked to 1Malaysia Development Bhd (1MDB) to the Monetary Authority of Singapore (MAS), prompting an investigation of the accounts involved, a person familiar with the matter said.

The transactions were not immediately recognised by UBS as suspicious, said the person, who asked not to be identified because the matter is private.

At least US$1.24 billion (S$1.67 billion) was transferred in 2014 from the account of a 1MDB subsidiary held at BSI SA in Lugano, Switzerland, to a UBS account in Singapore held by what appeared to be a unit of an Abu Dhabi company, UK-based investigative blog Sarawak Report said on July 11.

A spokesman for UBS declined to comment on the 1MDB transfers. When asked about the UBS case, the Singapore regulator referred to its previous statements made on March 31 and May 24.

MAS has said it is conducting supervisory reviews of several financial institutions and bank accounts through which suspicious and unusual transactions have taken place, without identifying the parties involved.

The Malaysian sovereign wealth fund is at the centre of probes in its home country and other jurisdictions including Singapore, Switzerland and the US as regulators seek to determine if some of the billions of dollars it raised were siphoned off.

While 1MDB has denied wrongdoing, a Malaysian parliamentary committee in April identified at least US$4.2 billion of questionable transactions, including those involving Abu Dhabi companies.

Singaporean regulators said in May they will strip BSI's local unit of its banking licence amid global investigations surrounding 1MDB. BSI was fined S$13.3 million for 41 breaches, including its failure to conduct due diligence on high-risk accounts and monitor suspicious customer transactions.