Malaysian acting Transport Minister Hishammuddin Hussein Sunday denied that there was a phone call made by the missing plane's co-pilot when the plane was flying low on the way, which was reported by local newspaper.

However, he said the issue would be in the realm of the police and other relevant international agencies and would be revealed when the time came.

Hishammuddin also said according to current investigation, there was no suspicious circumstance on the passenger manifests, while the police were still investigating the four possibilities, which were hijacking, issue of terrorism, psychological and personal problems.

He also revealed that Malaysia was discussing with relevant authorities and experts on the custody of the black box of the missing MH370 flight.

Attorney-General Abdul Gani Patail was now in Britain to discuss the issue with parties, which included international agencies like the International Civil Aviation Organization (ICAO), he said.

"The attorney general is in the UK discussing with relevant authorities such as ICAO and experts involved, based on international and domestic laws, who actually does have custody of the black box," he said at a press conference after visiting the Defense Services Asia exhibition site here. However, the focus was always on locating the plane first, he added.