A prominent Maltese businessman has offered to testify against top government officials over the 2017 murder of journalist Daphne Caruana Galizia and said the prime minister has a conflict of interest in the case.

Lawyers for the businessman, Yorgen Fenech, on Thursday deposited in court a letter to President George Vella formally asking for a pardon.

In return, Fenech promised to supply information related to former government chief of staff Keith Schembri, former Tourism Minister Konrad Mizzi, Economic Affairs Minister Chris Cardona and other people "close to the prime minister."