The high-resolution spectrum of the ν 1 =5 stretching overtone of gaseous H 70 GeD 3 has been recorded by an intracavity laser absorption spectrometer based on a vertical external cavity surface emitting laser (VECSEL). The rotational structure of the excited state at 9874.605cm −1 was found weakly perturbed by unidentified interaction with dark states. Finally, of the 313 lines rotationally assigned, 239 lines were found unperturbed and could be reproduced with a root-mean-square (rms) deviation of 0.012cm −1 . The retrieved set of rotational parameters agrees with the values extrapolated from the previously studied ν 1 =6–8 stretching overtones. High-resolution FTIR spectra of the ν 1 and 2ν 1 bands have also been recorded and analyzed. The ν 1 =1 level, (ν eff =2114.15cm −1 ) is in anharmonic interaction with a further A 1 symmetry level (ν eff =2102.39cm −1 ). The potential coupling term could be estimated (W anh =5.6(3)cm −1 ) and the most probable assignment of the perturber is ν 2 +ν 3 . Moreover both levels are rotationally perturbed in an irregular fashion. Only a coarse analysis up to J=6 could be performed. The 2ν 1 band reveals irregular perturbations of medium intensity by unknown dark states for almost all K values. Nevertheless the obtained leading rovibrational parameters of the 2ν 1 band for J⩽6 are in agreement with those of the ν 1 =5–8 states.