In an official statement released this morning by Voice370, the MH370 family support group, the families said since the plane went down, the had endured an agonising period in their lives.
"It's been 17 long months since contact was lost with MH370. Our nightmare continues. Most people can't even begin to imagine the pain and suffering we are being subjected to."
The families thanked the people of La Reunion, and French and Malaysian authorities, for their efforts since the flaperon was discovered almost two weeks ago.
"We are very thankful for the efforts of the many nations that have committed expertise and resources to help resolve this matter and bring relief to the agonising families."
However, the families said they were "apprehensive" about the handling of the incident by the Malaysian authorities from day one.
"This has led to families having doubts about their expertise, capabilities and intentions. Many of their announcements appear self-serving rather than serving the interests of the families, even though each announcement is touted to be made in the interest of the families."
In particular the families were critical of an announcement made by Malaysian Prime Minister Najib Razak last week, in which he confirmed that wreckage found on the French-administered island of Reunion was that of MH370.
A few hours after this announcement was made, French prosecutor Serge Mackowiak suggested, but would not confirm, the wreckage was from the missing Malaysia Airlines flight.
"A case in point is the latest announcement by the Prime Minister of Malaysia confirming the flaperon is from MH370 and yet again the inevitable finality of their conclusion," the families said in their joint statement.
"However, after one week, other experts have not concurred with the Malaysia declaration. Needless to say, most families have refused to accept the Malaysian verdict, and are awaiting a more definite and conclusive analysis."
In view of these concerns, the families appealed to authorities that all debris be analysed at a reputable place, with the appropriate expertise and equipment.
They explained that they wanted the world to know they were not living in denial.
"We are prepared for all eventualities. However, we are not prepared to give up on our loved ones unless and until there is 100 per cent certainty."