SINGAPORE, May 15 -- The Singapore Democratic Party has raised alarm over a photograph showing top government figures dining with two individuals under investigation for money laundering, saying it surfaced at a sensitive time just after the general election.

In a statement, the party said public trust in Singapore's political leadership was at stake.

"We call for a full and transparent investigation through a public and independent Commission of Inquiry," SDP said in a statement.

"Important questions need to be addressed to preserve Singapore's reputation for integrity and incorruptibility."

The SDP said it was crucial to determine whether the dinners were personal or official, and whether proper protocols were followed.

The party a...