US officials, according to an ABC News report, believe that two communication systems on MH370 may have shut down separately.

Unnamed US investigators was quoted by ABC News as saying that the two modes of communication were "systematically shut down."

“The data reporting system, they believe, was shut down at 1:07 a.m. The transponder -- which transmits location and altitude -- shut down at 1:21 a.m,” said the report.

“This indicates it may well have been a deliberate act,” said ABC News aviation consultant John Nance.

According to another anonymous source, the 'systematic shutdowns' indicate that the plane did not go missing because of a catastrophic failure.

The source told of the US broadcasting company that the US team "is convinced that there was manual intervention.”

Yesterday, MAS chief executive officer Ahmad Jauhari Yahya said that the last High-Speed transmission was at 1.07am and that “was the last transmission that we ever see from the aircraft, it did not run beyond that”.

Two days ago however, Department of Civil Aviation director-general Datuk Azharuddin Abdul Rahman had said the last posting was at 1.21am.

“In our secondary radar, we look at our radar and it was posting at about 1.21 in the morning, and the target disappeared at 1.30 in the morning,” he said.

These different times and seemingly contradictory statements have added to the confusion over the flight since the search and investigations began on Saturday.

Earlier, US officials said that they have an "indication" the missing Malaysia Airlines jetliner may have crashed into the Indian Ocean and is moving the USS Kidd to the area to begin searching.

The missing Malaysian flight continued to "ping" a satellite on an hourly basis after it lost contact with radar, according to US officials in another ABC News report.

This was not the first time that the possibility that MH370 has continued flying for hours was raised.

Yesterday, The Wall Street Journal reported that data automatically downloaded and sent to the ground from the Boeing Co 777's engine indicated that the plane flew for five hours after departing Kuala Lumpur.

The flight time of five hours after departing Kuala Lumpur means the plane could have continued for an additional distance of about 2,200 nautical miles, reaching points as far as the Indian Ocean, the border of Pakistan or even the Arabian Sea.

However, this report was dismissed by Datuk Seri Hishammuddin Hussein on Thursday.