Read more:
• 'Suspicious objects' spotted
• Hunt for MH370: What you need to know
• MH370: Plane's captain 'got mystery call'
"We have a rule that no-one in the family is allowed to cry or mention this issue in front of her," Mrs Liu said.
"She wouldn't be able to cope with this news about her father... I really just want my son to come home and to be safe. My heart is broken. My son is definitely going to be all right."
The interview, aired by the state-owned China Central Television, emerged as the multinational search for the aircraft was given a fresh lead following a third sighting of apparent debris.
A relative of passengers aboard the missing Malaysia Airlines flight expresses her frustration at the lack of information. Photo / AP
A French satellite detected "potential objects" in a remote stretch of the southern Indian Ocean, north of two earlier sightings. An initial sighting by a US satellite just over a week ago was of two floating objects, 24m long, in deep waters about 2400 kilometres south-west of Perth. A second sighting, by a Chinese satellite, found an object 72ft long.
The French authorities did not give details but an official said the new French data consisted of radar echoes captured on Friday, and converted into fuzzy images. The objects were 925 kilometres north of the area where those discovered by Australia and China were located, suggesting they may be unconnected.
One was estimated to be about the same size as the object spotted by the Chinese satellite.
Flight Officer Stuart Doubleday, on board a Royal Australian Air Force AP-3C Orion, scans for the missing Malaysia Airlines flight. Photo / AP
But an expanding air and sea search across an area spanning almost 23,000 square miles has yet firmly to identify any wreckage from the plane.
A civilian plane spotted other small objects on Saturday, believed to include a wooden pallet, a multicoloured belt and other, smaller, items but authorities have yet to identify precisely where they would now be located, given the region's notoriously strong winds and currents. A New Zealand air force plane flew over the area later and spotted only seaweed.
A Malaysia Airlines official last night confirmed the Boeing 777 had been carrying wooden pallets.
Ships and planes were sent yesterday to look for the pallet but failed to turn up any "sightings of significance", the Australian Maritime Safety Authority said.
"It's a possible lead, but we will need to be very certain... because pallets are used in the shipping industry as well," said Mike Barton, an agency official.
Despite sea fog and low cloud hampering the search, authorities were buoyed by the new French sighting.
Investigators have long believed that the plane's most likely end point was in the southern Indian Ocean; an alternative northern trajectory towards Kazakhstan has been effectively ruled out.
"There is increasing hope - no more than hope - that we might be on the road to discovering what did happen to this ill-fated aircraft," said Tony Abbott, Australia's prime minister.
Royal Australian Air Force pilot Capt. Russell Adams, left, speaks to the media after returning from a search mission. Photo / AP
The plane's disappearance 16 days ago during a routine flight from Kuala Lumpur to Beijing appears little closer to being explained, despite an investigation that has drawn in aviation experts, extensive radar analysis and advanced technology from at least 26 countries.
Flight MH370 took off as planned at 12.41am on March 8, but within an hour its on-board communications systems had been disabled - apparently deliberately - and it took a sharp, unexpected turn westward while flying at 35,000ft above the Gulf of Thailand. Though the aircraft disappeared from radars, satellite pings from its communications system later showed that it flew silently for seven hours after changing course.
The police investigation in Kuala Lumpur has focused on Zaharie Ahmad Shah, the 53-year-old pilot and father of three, and Fariq Abdul Hamid, the 27-year-old co-pilot, who was planning to marry his girlfriend, who is also a pilot. Both were experienced fliers; neither had any background of extremism or psychological problems.
Investigators have also examined the cargo manifest, including details of potentially dangerous batteries that were being carried, which could theoretically have started a fire. Malaysia Airlines said all were packed according to regulations but refused to release the manifest because the investigation is continuing. The Australian Maritime Safety Authority said it had sent a request for the cargo manifest to Malaysia Airlines.
Liu Guiqiu, the anguished mother of a passenger from Malaysia Airlines flight MH370. Photo / AP
Meanwhile, unable to endure the wait in Beijing, Mrs Liu was among those who flew to Kuala Lumpur to confront the Malaysian authorities directly.
Last Wednesday, she and other family members held a protest at a media briefing, which led to a scuffle as officials dragged the screaming people away. It was during this melee that Mrs Liu could be seen as she wailed in desperation.
"At that stage, the plane had been missing for 12 days," she said. "I can't understand why there hasn't been any news. There has been no news about my son, none at all."
In tears, she shook her head and added: "I'm going to be crazy."
Describing the confrontation that was seen around the world, she said: "I was surrounded by reporters. There was a policeman who I initially thought was about to grab me. I said, 'what are you doing? Help!' Then they put me aside... I just want to see my son return."
Kneeling down and holding her hands together in supplication, Mrs Liu offered gratitude to the countries "trying to find our families".
"I should kowtow to everyone helping the search and rescue," she said. "Thank you for searching for our families."
- Additional reporting by Adam Wu
