A near-infrared Ks-band image of the source from the VVV survey (0.5′′  resolution) is shown using inverted grey scale and logarithmic intensity stretch. The circle marks the 24′′ beam of the 1.2 mm observations that uncovered the cold and dense (n_H2 = 5.44 × 10⁴ cm^-3) molecular clump (Mookerjea et al. 2004), with an estimated mass of ~15 000 M_⊙  and a radius of 1.88 pc. Intense line emission from a variety of molecular species (CO, CS, HCO⁺, HCN, HNC, C₂H) is detected from this clump (Lo et al. 2009). The bipolar-shaped nebula and the dark lane are identical in morphology to the UCHII region (Fujiyoshi et al. 2006). The dark lane (size ~ 30 000 AU) may represent a hot core/toroid seen edge-on, but further analysis here indicates that it may actually represent the low-density part of the red-shifted outflow cavity (see Sect. 5).