Singapore Prime Minister Lee Hsien Loong has been diagnosed with prostate cancer and will undergo surgery on Monday, but is expected to recover fully after a week's medical leave, his office said Sunday.

It is the second bout with cancer for Lee, who was diagnosed with lymphoma in 1993, for which he underwent chemotherapy and is now in remission.

Singapore police said Monday they were investigating after Facebook posts showing photographs of bullets were addressed to the prime minister of the city-state, which prides itself on its stability and security.

"Police confirm reports have been lodged and investigations are ongoing," a Singapore Police Force spokesman told Agence France Presse without providing further details about the posts tagging Prime Minister Lee Hsien Loong.

Indonesian divers have found a body believed to be the French co-pilot who was steering an AirAsia plane when it crashed in December with 162 people onboard, an official said Saturday.

Coordinator of the search and rescue effort S.B. Supriyadi said the body was retrieved from the front part of the fuselage during a search operation on Friday.

Indonesian President Joko Widodo arrived in Malaysia on Thursday for his first bilateral trip abroad, with the two sides hoping to shore up an important Southeast Asian relationship frequently strained by diplomatic spats.

Widodo, who took office last October, and his host Prime Minister Najib Razak will discuss a range of issues including sticky disputes on maritime borders and the treatment of Indonesian migrant workers in Malaysia, Jakarta's foreign minister spokesman Arrmanatha Nasir told Agence France Presse.

A former top U.S. Navy officer was arrested Tuesday over a bribery scandal centered on a Singapore-based contracting firm, in which seven people have already pleaded guilty, officials said.

Paul Simpkins, 60, was arrested in Virginia and charged with conspiracy to commit bribery for his alleged role in a scheme to steer contracts to defense contracing company Glenn Defense Marine Asia (GDMA).

Indonesian divers on Monday found another six victims of the AirAsia plane crash, an official said, taking to 84 the number of bodies retrieved since the accident in late December.

Two bodies were found inside the fuselage of the plane, while another four were located near the wreckage on the bottom of the Java Sea.

The French co-pilot was at the controls of an AirAsia plane when it crashed into the sea last month after flying through an area of towering clouds, killing all 162 people on board, investigators said Thursday.

The announcement came as fishermen found two more bodies from the crash in waters off Sulawesi island in central Indonesia, around 1,000 kilometres (600 miles) from where the plane crashed, a search and rescue official said.

Hopes faded Wednesday of finding 92 victims still missing from an AirAsia plane crash as Indonesian search and rescue authorities said the remaining bodies could have been swept away or lost on the seabed.

Flight QZ8501 went down in the Java Sea on December 28 in stormy weather with 162 people on board, during what was supposed to be a short trip from the Indonesian city of Surabaya to Singapore.

Indonesian salvage teams failed again Sunday to retrieve the fuselage of AirAsia Flight 8501 from the seabed after a sling snapped during a sudden change in the weather, officials said.

In the past two days the teams have been using giant inflatable bags to raise the fuselage, which lies in the Java Sea at a depth of around 30 metres (98 ft), to make it easier to find bodies believed trapped inside. 

Indonesian divers on Friday finally reached the fuselage of an AirAsia plane that crashed last month, an official said, as four more bodies were recovered from the Java Sea.

Flight QZ8501 went down on December 28 in stormy weather with 162 people on board as it flew from the Indonesian city of Surabaya to Singapore.