Singapore has seized a “large number” of bank accounts over possible money laundering offences linked to an international investigation into the Malaysian state investment fund 1MDB, authorities in the city-state said on Monday. In an illustration of the mounting pressure from global regulators on the troubled fund, Singapore confirmed that it was “cooperating closely” with relevant authorities in Switzerland and the US. The Swiss attorney general announced on Friday that there were “serious indications” that $4bn had been misappropriated from Malaysian state companies and that a portion of the funds was transferred to accounts held in Switzerland.