  Employing the Bonn-Gatchina partial wave analysis framework (PWA), we have
analyzed HADES data of the reaction $p(3.5GeV)+p\to pK^{+}\Lambda$. This
reaction might contain information about the kaonic cluster "$ppK^-$" via its
decay into $p\Lambda$. Due to interference effects in our coherent description
of the data, a hypothetical $\overline{K}NN$ (or, specifically "$ppK^-$")
cluster signal must not necessarily show up as a pronounced feature (e.g. a
peak) in an invariant mass spectra like $p\Lambda$. Our PWA analysis includes a
variety of resonant and non-resonant intermediate states and delivers a good
description of our data (various angular distributions and two-hadron invariant
mass spectra) without a contribution of a $\overline{K}NN$ cluster. At a
confidence level of CL$_{s}$=95\% such a cluster can not contribute more than
2-12\% to the total cross section with a $pK^{+}\Lambda$ final state, which
translates into a production cross-section between 0.7 $\mu b$ and 4.2 $\mu b$,
respectively. The range of the upper limit depends on the assumed cluster mass,
width and production process.
