A clerk and a driver who transported the mail were arrested and the bags, one of which contained letters to a state minister, were recovered from them yesterday, police said.
The duo told police during questioning that the bags had been kept hidden in the clerk's house, they said adding, however, the motive of the act was still to be ascertained.
The RMS had in May filed a complaint that the postal bags were not reaching various zones in Salem postal division, said Inspector Vincent, attached to Pallipatty police station here.
Railways sources said five employees handling the mail had been transferred to other districts.