It is being claimed the plane carrying Deputy President Kgalema Motlanthe, which was forced to land in the Democratic Republic of Congo two weeks ago, may have been flying without a working fuel gauge.

Reports last week indicated how the plane touched down on an unlit airstrip, burst a tyre upon landing and was then surrounded by Congolese soldiers.

The Democratic Alliance said modifications were made to the DC-9 to extend its range which meant the gauge was disconnected.

"The plane that was carrying the deputy president did not have a fuel gauge, so whether the pilots could calculate more or less how much fuel they were burning once they could not land at their intended destination in the Central African Republic, they were in trouble," said DA MP James Lorimer.