Two trips to Madagascar to pick up what might be debris from the plane have been cancelled at the last minute, according to the man that found them.
The potential clues have been left untouched for weeks, with no prospect of them being gathered and examined.
"Credible evidence is turning up, why are they not investigating it?" Grace Subathirai Nathan told the BBC.
Her mother, Anne Daisy, was on MH370 when it disappeared in March 2014.