Ewan Wilson, a former Kiwi International Airlines chief executive, who wrote the book "The Truth Behind the Loss of Flight 370", suggested that the pilot of the flight committed murder-suicide. The book has been co-authored by Geoff Taylor.
The duo were promoting the book in England this week. They claim MH370 was the sixth commercial flight to crash because of suicidal or mentally ill pilots.
The book claims pilot Zaharie Ahmad Shah of MH370 deliberately depressurised the cabin, giving passengers only 20 minutes' oxygen supply, and locked his co-pilot out of the cockpit.
Malaysia Airlines said it was "appalled" at the claims, the New Zealand Herald reported Thursday.
"There is no evidence to support any of the claims made in the book. It is not more than a conclusion formed on the basis of incomplete information," Malaysia Airlines said a statement.
It said the authors should "be ashamed of themselves" for "seeking to make money on the suffering of the families and undermining the dignity of all of those on board".
New Zealanders Ximin Wang and Paul Weeks were among the 239 people on board MH370.
MH370 had taken off from Kuala Lumpur early March 8 headed for Beijing but disappeared from the radar soon after. Despite a large-scale international search, no trace of the flight has been found till date.