2. Whether having regard to the totality of the evidence adduced the Court of Appeal was right in affirming the conviction of the Appellant for being in unlawful possession of Indian hemp. The two issues whether of the Appellant or the Respondent are inter woven and best taken together to resolve the dispute as to the rightness or not of the Court below. It really does not matter whose issues is taken but I shall just for convenience utilise those of the Appellant and taken together. Issues 1 & 2: These issues are in the main asking the question whether from the evidence before the trial court proof beyond reasonable doubt that the substance allegedly recovered from the Appellant was indeed cannabis sativa also known as India Hemp and whether the two Lower Courts were right in finding for the prosecution and proceeding to convict and sentence the Appellant. Learned counsel for the Appellant submitted that there are three essential ingredients of the alleged offences which must be proved beyond reasonable doubt and which are thus:i. The possession must be within the knowledge of the Accused. ii. Unlawful possession of the substance known as Indian hemp. iii. That the substance is Indian hemp That all three ingredients must be proved beyond reasonable doubt. He said in the proof theory the prosecution has the onus of effecting the following:i. The alleged substance is scientifically tested by a Government Chemist. ii. The said test must establish that the substance in question is Indian Hemp. iii. The Accused must be carried along in every step taken in testing the substance. iv. There is no opportunity for anybody to substitute and or intermeddle with the substance. He cited Section 10H of the NDLEA Act No 15 of 1992, Alabi v State (1993) 7 NWLR (Part 306) 511 at 516; Ishola v The State (1969) 1 NMLR 259; Onah v State (1985) 3 NWLR (Part 12) 236; Akinfe v State (1988) 3 NWLR (Part 85) 729 at 745. Mr. Ogunsanya further contended that from the Record of Proceedings the substance was tested by the Exhibit Keeper and not by an Expert as required by law. He referred to Azu v State (1993) 6 NWLR (Part 299) 303 at 311 E - H; Njoku v State (1993) 6 NWLR (Part 299) 272 at 274; Section 65 of the Evidence Act. He stated that it is trite that the basis for the opinion or conclusion of an expert must be given otherwise the opinion or conclusion of the said expert will be rejected. He referred to the evidence of PW2 and the case of Arisa v The State (1988) 3 NWLR (Part 83) 386 at 398. Learned counsel said from the record, on 18/7/2002 the Exhibits were in the custody of the Trial Court and so where did PW2 get the sample he took to Lagos on 8/12/2004. That a doubt existed since the prosecution had contradictions in their evidence which doubt has to be resolved in favour of the accused/appellant. That there also was present doubt as to whether Exhibit “E” is the result of the analysis of Exhibits D1 - D12 and that by virtue of Section 43 of the Evidence Act, the appellant was entitled to be served with the purported certificate at least 10 clear days before the hearing but was only served on the hearing day. He cited Bozin v State (1985) 2 NWLR (Part 8) 465 at 467. Mr. Ogunsanya of counsel stated on that from the Record the said DAF Truck had occupants such as driver, conductor and other passengers who are material witnesses in resolving whether the Appellant was in the said DAF Truck or not. That there is no limit as to the number of witnesses that Prosecution must call but failure to call a material witness is fatal to the case of the prosecution because the fate of an accused person should not be determined based on the unverified and scanty evidence of prosecution witnesses. That this court should interfere with the concurrent findings of the two Lower Courts. He cited Alabi v State (1993) 7 NWLR (Part 307) 511 at 516; Adaje v State (1979) 6 - 9 SC 18 at 28; Okonofua v State (1981) 6 - 7 SC 1 at 18; Alake v State (1992) 9 NWLR (Part 265) 260 at 263; Shehu v State (2010) 22 WRN 1 at 9; Oludamilola v State (2010) 15 WRN 1 at 3. Responding, Mr. Okpoko learned counsel for the Respondent contended that the preliminary field test was conducted by PW2. That the recovered drug exhibits were packed and sealed in the presence of the Appellant on the same date of arrest and so this