The WSJ reports that authorities in China are investigating claims that two of Apple’s suppliers – Foxconn and UniMicron – are releasing water polluted by heavy metals into local rivers.

The reports follow recent allegations about working conditions at another Apple supplier, Pegatron.

China does not have the best reputation when it comes to pollution, with lax regulation poorly enforced, but the specific allegations here appear rather vague.

Apple says that it does not tolerate environmental violations and carries out regular audits of its suppliers.