Sewage pollution of Scotland’s rivers and beaches is far more widespread than realised because ministers have failed to take the problem seriously, an environment watchdog has found.

Environmental Standards Scotland (ESS) said there were thousands of sewage overflow incidents last year, and that nearly half of the country’s storm overflows released sewage more than 50 times.

Of those, a third released sewage at least 100 times, and four sites more than 500 times. Few of these incidents were publicly disclosed; most failed to be justified as exceptional.