A search is presented for QCD instanton-induced events in Deep-Inelastic Scattering (DIS) at the electron-proton collider HERA in a kinematic region defined by the Bjorken-scaling variables x > 10^-3, 0.1 < y < 0.6 and photon virtualities 10 \lesssim Q² < 100 GeV. Several observables characterising hadronic final state properties of QCD instanton-induced events are exploited to identify a potentially instanton-enriched domain. While an excess of events with instanton-like topology over the expectation of the standard DIS background is observed it cannot be claimed to be significant given the uncertainty in the predictions for the background. Upper limits on the cross-section for instanton-induced processes are set and compared to non-perturbative lattice simulations of the QCD vacuum.

PACS numbers: 12.38.Lg, 12.38.Qk, 13.60.Hb