A particularly dangerous batch of ecstasy has landed nine people in hospital in Christchurch.

People arrived at the Christchurch Hospital's Emergency Department in an agitated state last night, with dangerously high blood pressure and elevated heart rates.

They all had symptoms and side effects associated with having taken a substance containing MDMA - Methylene-dioxy-methamphetamine - more commonly known as ecstasy.

Doctor Suzanne Hamilton says people who may be in possession of the dodgy substance should flush it down the toilet.

Dr Hamilton says the drug is more dangerous than usual, and people who may be in possession of the dodgy ecstasy are urged to flush it down the toilet.

Canterbury District Health Board says as the patients turned up in such a short space of time and in one place, a faulty batch of ecstasy may be responsible.