Family members of kidnap victim Bernard Then Ted Fen will head to Manila, Philippines this week to claim his remains for cremation there and bring his ashes home.

Inspector General of Police Tan Sri Khalid Abu Bakar said arrangements had been finalised with the cooperation of his counterpart and Wisma Putra.

"Malaysian police will render the necessary assistance and my officers will also accompany the family," he told reporters after the monthly assembly at Bukit Aman here today.

Then, from Sarawak was abducted from a seafood restaurant in Sandakan, Sabah on May 14, 2015, together with the restaurant's manager Thein Nyuk Fun, 50, by armed men believed to be linked to a militant group from southern Philippines.

Nyuk Fun was freed by their captors on Nov 8, while Then, 39, was beheaded at a remote location on Jolo Island, southern Philippines on Nov 11.

Meanwhile, Khalid said Malaysian police were scrutinising a document related to the investigation on Petrosaudi International former executive Xavier Andre

Justo, which was received from the Attorney General's Chambers in Thailand.

"There are about 4,000 emails in the document... we need time to study all of them," he said.

Last Dec 16, Khalid confirmed that Malaysian police had recorded Justo's statement on the 1Malaysia Development Berhad (1MDB) issue, which was done from a prison in Bangkok.

He was confident that the document from the Thai authorities would facilitate completion of the case involving Justo.

Justo was sentenced to three years in prison by the Southern Bangkok Criminal Court on Aug 17, 2015 after pleading guilty to stealing 90 gigabytes of data including emails, documents and other material from PetroSaudi International with intention to blackmail.