Is it tru th mitochondria are derived fr female parent only in us?

Check this:
http://en.wikipedia.org/wiki/Paternal_mtDNA_transmission#In_humans
Note that there is a debate on this matter, but it's generally accepted that only mitochondrea from the ovum are found in the zygote, while the mitochondrea from the sperm cell are lost after fertilization.

Since the father's mtDNA is located in the sperm midpiece (the mitochondrial sheath), which is lost at fertilization, all children of the same mother are hemizygous for maternal mtDNA and are thus identical to each other and to their mother. Because of its cytoplasmic location in eukaryotes, mtDNA does not undergo meiosis and there is normally no crossing-over, hence there is no opportunity for introgression of the father's mtDNA. All mtDNA is thus inherited maternally; mtDNA has been used to infer the pedigree of the well-known "mitochondrial Eve."

(From the provded link. Read the wikipedia article further for some other interesting things.)

Finally, you asked how it can be verified? My guess is that the method is similar to this used to DNA to determine the person who did a crime etc.
DNA has some regions called Genetic markers http://en.wikipedia.org/wiki/Genetic_marker .
Genetic markers usually differ from person to person, because of mutations that may have happened during the generations.. To determine whose the DNA is, a number of genetic markers are tested. If they are found identical to a person, then it is very likely that the DNA belongs to him. (possibility of false results is very small).
For mitochondrial DNA I guess a similar process is being used. Note that relatives may have very similar or even identical mitochondrial DNA if they share a female generation line because the mtDNA is passed only from the mother to the offsprings (on the other hand, relatives do not have very similar or identical chromosomal DNA, exept for identical twins)

Do you want to know the whole process that is used? It is quite complicated.