Malaysia is in discussion with the relevant authorities and experts on who actually has the custody over the black box of the missing Malaysia Airlines flight MH370.

Acting Transport Minister Datuk Seri Hishammuddin Tun Hussein said Attorney-General Tan Sri Abdul Gani Patail was currently in the United Kingdom to discuss the matter including with international agencies such the International Civil Aviation Organisation (ICAO).

"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 told reporters after visiting the Defence Services Asia exhibition site, here Sunday.

The Boeing 777-200ER is registered in Malaysia and owned by MAS. And under the ​ Convention on International Civil Aviation, the country of origin of the aircraft, which is Malaysia, is obliged to launch an investigation and secure the wreckage.

However, Malaysia has asked Australia to lead the search in the southern Indian Ocean.

He, however, reiterated that the focus was always on locating the plane first, which has been missing for 37 days since it disappeared from radar screens on March 8.

Hishammuddin also said that there was no telephone call made by MH370 co-pilot Fariq Abdul Hamid when the plane was flying low on the day it disappeared as reported in the 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.

"I don't want to speculate on that, because out of respect of the families of the pilot and co-pilot, and I don't want to disturb the investigations being done now, not only by Malaysian police but other intelligence agencies," he said.

Hishammuddin also stated that based on current investigation, there was no suspicious circumstances on the passenger manifests and the police were still investigating the four possibilities on the MH370 disappearance.

"The police are still investigating the possibility of hijacking, issue of terrorism, psychological and personal problems," he said.

Flight MH370, carrying 227 passengers and 12 crew, left the KL International Airport at 12.41am and disappeared from radar screens about an hour later, while over the South China Sea. It was to have arrived in Beijing at 6.30am on the same day.