Water industry regulator Ofwat has launched an "enforcement investigation" into South West Water.
The water company, which is owned by Exeter-based Pennon Group, is under scrutiny regarding the accuracy of information reported for its performance on leakage and per capita consumption (PCC).
Ofwat sets performance targets for companies on leakage and PCC. Companies are assessed against these targets annually and can be penalised or rewarded, depending on their performance. The regulator investigates water companies when it believes there may be a breach of an obligation that Ofwat has powers to enforce.